![Important Physical Units
In the following we will list important electrical quantities and their usual definitions.
Voltage U [Volt, V]: 1 V is the difference in electric potential between
two points of a conductor carrying a constant cur-
rent of 1 A, when the power dissipated between
those points is equal to 1 W.
Resistance R [Ohm, Ω]: 1 Ω is the resistance of a conductor such that a
constant current of 1 A produces a voltage drop of
1 V between its ends.
Conductance g [Siemens, S]: The inverse of the resistance R.
Current I [Ampere, A]: 1 A is that constant current which, if maintained in
two straight parallel conductors of infinite length,
of negligible circular cross section, and placed one
metre apart in a vacuum, would produce between
these conductors a force equal to 2 107
Newton
per 1 m of length.
Charge Q [Coulomb, C]: 1 Coulomb equals the charge of 6.25 1018
ele-
mentary charges e.
Capacitance C [Farad, F]: 1 F is the capacitance of a capacitor between the
plates of which there appears a difference of poten-
tial of 1 volt when it is charged by a quantity of
charge equal to 1 coulomb.
Magnetic Flux Density B [Tesla, T]: 1 T is the density of a homogenous magnetic flux
of 1 Weber (Wb) perpendicular to an area of 1 m2
:
1T ¼ 1 Wb/m2
.
Volt: V ¼ W
A ¼ kgm2
As3
Ohm: Ω ¼ V
A ¼ kgm2
A2
s3
Siemens: S ¼ 1
Ω ¼ A2
s3
kgm2
xi](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-12-320.jpg)
![Abbreviations
γ Single-channel conductance, activity coefficient
δ Quantisation step, charge density
ε0 Polarisability of free space
η Viscosity
λ Length constant
μ (Electro)chemical potential
ρ Specific resistance
τ Time constant
a Activity
A Gain (op-amplifier), area
ASM Airway smooth muscle
AU Arbitrary unit
au Arbitrary units
B Bandwidth
C Capacitance
c Concentration
Ca2+
i Intracellular calcium activity
CypA Cyclophilin A
D Diffusion coefficient, dissipation factor (capacitor)
DOR δ-opioid receptor
DPDPE [D-Pen2
,D-Pen5
]enkephalin
e Elementary charge
E, V, Φ Electric potential
EAAC Excitatory amino acid carrier
EC ()-epicatechin
EGCG ()-epigallocatechin-3-gallate
F Faraday’s constant
f Frequency
FBA Feedback amplifier
G Gibb’s energy
GA Glycyrrhizic acid
xix](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-19-320.jpg)
![remorse becomes appeased; as in former days, the proscribed
found, at the foot of the altar, an asylum against the fury of men.
Marriage is generally assumed as a means of increasing credit and
fortune, and of assuring success in the world. It should be
undertaken as a chief element of happiness, in the retirement of
domestic repose.[28] I would wish that my disciple, while still in the
freshness of youth, might have reason and experience enough to
select the beloved person, whom he would desire one day to
espouse. I would hope, that, captivated with her dawning qualities,
and earnestly seeking her happiness, he might win her tenderness,
and find his satisfaction in training her to a conformity to his tastes,
habits and character.
The freshness of her docile nature demands his first forming
cares. As she advances in life she is moulded to happy changes,
adapted to supply his defects. She is reared modest, amiable,
instructed, respectable, and respected; one day to govern his family,
and direct his house, by diffusing around the domestic domain, order
and peace. Let neither romances, metaphysics, pedantry nor fashion
render a qualification for these important duties, either trifling or
vulgar in her view. Still, domestic duties are by no means to occupy
all her hours. The time which is not devoted to them will flow quietly
on in friendly circles, not numerous, but animated by gayety,
friendship and the inexplicable pleasures which spring from
intercourse with rational society. There are, also, more unimportant
duties, which we expect her not to neglect. We wish her to occupy
some moments at a toilet; where simplicity should be the basis of
elegance; and where native tact might develope the graces, and
vary, and multiply, if I may so say, the forms of her beauty. In fine,
the versatility of her modes of rendering herself agreeable, should
increase the chances of always escaping ennui in her presence.
But train women to visit a library as savans, and they will be likely
to bring from it pedantry without solid instruction; and coquetry
without feminine amiability. I would not be understood to question
the capability of the female understanding. I am not sure that I](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-22-320.jpg)
![would wish the wife of my friend to have been an author, though
some of the most amiable and enlightened women have been such.
But I deem that in their mental constitution, and in the assignment
of their lot, providence has designated them to prefer the graces to
erudition; and that to acquire a wreath of laurels, they must
ordinarily relinquish their native crown of roses.[28a] When we see a
husband and wife thus united by tenderness, good hearts and
simple tastes, everything presages for them a delightful futurity. Let
them live contented in their retirement. Instead of wishing to blazon,
let them conceal their happiness, and exist for each other. Life will
become to them the happiest of dreams.
Perhaps the world will say, ‘you speak, it may be, of such a wife as
you would be understood to possess yourself. But you do not paint
marriage in the abstract, while you thus describe happiness as
finding a habitation within the domestic walls, and pain and sorrow
without: how many people find eternal ennui at home, and respire
pleasure, only when they have fled their own threshold.’ There are
few wives so perfect, says La Bruyere, ‘as to hinder their husbands
from repenting at least once in a day, that they have a wife; or from
envying the happiness of him who has none.’
This sentence, instead of containing a just observation, is only an
epigram. In looking round a circle of individuals, ridiculously called
the world, we shall find happy family establishments less rare than
we imagine. Besides, it would be absurd to count among unhappy
unions, all those which are not wholly exempt from stormy passions.
Not only is perfect felicity a chimerical expectation on the earth, but
we meet with many people who would be fatigued into ennui in a
perfect calm, and who require a little of the spice of contrariety to
season the repast of life. I would not covet their taste; but there are
modes of being singular, which, without imparting happiness,
procure pleasures. Finally, supposing the number of unhappy
marriages to be as immense as is contended, what is the
conclusion? The great majority adopting, as maxims of life, principles](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-23-320.jpg)
![scenes of pain and affliction, and the agony of the sick and dying
bed. In a word, all argument apart, nature has clearly demonstrated
to which sex authority belongs.
I discover that the defects of man spring from the tendency of his
natural traits, in which force predominates, to run to excess. I see
his gentle companion endowed with attributes and qualities naturally
tending to temper his defects. The means she has received to reach
this end announce that it is the purpose of nature that she should
use them with this view. She has charms which, when rightly
applied, none can resist. Her character is a happy compound of
sensibility, wisdom and levity. She has superadded a felicity of
address which she owes to her organization, and which the reserve,
that her education imposes, serves to develope. Thus the qualities,
and even the imperfections of the two sexes serve to bring them
together. It follows, that man should possess authority, and woman
influence, for their mutual happiness.
When the wife commands, I cease to behold a respectable
married pair. I see a ridiculous tyrant, and a still more ridiculous
slave. It is vain to urge that she may be most capable of authority,
and that her orders may be conformable to wisdom and justice.
They are absurd, from the very circumstance that they are orders.
The virtues which the husband ought to practise towards his wife
must have their origin in love, which can only be inspired, and which
flies all restraint. In a single position, the wife honors herself in
assuming authority. It is when reverses have overwhelmed and
desolated her husband, so that, ceasing to sustain her and changing
the natural order, she supports him. Grant that he receives hope as
her gift; grant that he is compelled to blush in imitating her example
of courage; she aspires to this power no longer than to be able to
restore him to the place whence misery had cast him down.[30]
It is a truth that ought not to be contested, that dissatisfied
husbands and wives often love each other more than they imagine.
Suppose them to believe themselves indifferent; and to seem so;
and even on the verge of mutual hate; should one of them fall sick,](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-26-320.jpg)
![L E T T E R X V.
C H I L D R E N .
One of the happiest days, and, perhaps, the most beautiful of life,
is when the birth of a child opens the heart of the parent to
emotions, as yet, unknown.[31] Yet what torments are prepared by
this epoch! What painful anxiety, what agonies their sufferings
excite! What terror, when we fear for their infant life! These alarms
terminate not with their early age. The inquietude with which their
parents watch over their destiny fills every period of their life to their
last sigh.
The compensating satisfaction which they bring must be very
vivid, since it counterbalances so many sufferings. In order to love
them, we have no need to be convinced that they will respond to
our cares, and one day repay them. If there be in the human heart
one disinterested sentiment, it is parental love. Our tenderness for
our children is independent of reflection. We love them because they
are our children. Their existence makes a part of ours; or, rather, is
more than ours. All that is either useful or pleasant to them, brings
us a pure happiness, springing from their health, their gayety, their
amusements.
The chief end which we ought to propose to ourselves, in rearing
them, is to train and dispose them so that they may wisely enjoy
that existence which is accorded them. Of all the happy influences
which can be brought to bear upon their mind and manners, none is
more beneficial than the example of parental gentleness. The good
Plutarch most eloquently advanced this doctrine in ancient time.
Montaigne, Rousseau, M’Kenzie, and various writers of minor fame
among the moderns, have reproduced his ideas, and, by their
authority, have finally effected a happy revolution in education. I
delight to trace the most important ideas thus reproduced by
enlightened and noble minds in different ages. It is chiefly by](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-29-320.jpg)
![his reason, and by his eagerness to cultivate the sciences, which,
instead of producing fatigue or disgust, will every day give birth to
new ideas and new pleasures. I am nevertheless little surprised, that
the scrupulous advocates of the existing routine should insist that
such a method tends to form superficial thinkers. I can only say to
these profound panegyrists of the present order of instruction, that
the method which I recommend, was that of the Greeks.—Their
philosophers taught while walking in the shade of the portico or of
trees, and were ignorant of the art of rendering study tiresome, and
not disposed to throw over it the benefits of constraint. Modern
instructers ought, therefore, to find that they were shallow
reasoners, and that their poets and artists could have produced only
crude and unfinished efforts.[33]
Besides, this part of education is of trifling importance, compared
with the paramount obligation to give the pupil robust health, pure
morals, and an energetic mind. I deeply regret that the despotic
empire of opinion is more powerful than paternal love. Instead of
gravely teaching to your son the little arts of shining in the world,
have the courage to say to him, ‘oblige those of thy kind whose
sufferings thou canst lighten, and exhibit a constant and universal
example of good morals. Form, every evening, projects necessary
for enjoying a happy and useful succeeding day.’ Thus you will see
him useful, good and happy, if not great in the world’s estimation.
You will behold him peacefully descending the current of time. In
striking the balance with life, he will be able to say, I have known
only those sufferings which no wisdom could evade, and no efforts
repel. But such are the prejudices of the age, to give such counsels
to a son requires rare and heroic courage.
Is not that filial ingratitude, of which parents so generally
complain, the bitter fruit of their own training?—You fill their hearts
with mercenary passions, and with measureless ambition. You break
the tenderest ties, and send them to distant public schools. Your
children, in turn, put your lessons to account, and abandon your
importunate and declining age, if you depend on them, to mercenary](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-33-320.jpg)
![hands. When they were young, you ridiculed them out of their
innocent recklessness, and frankness, and want of worldly wisdom.
You vaunted to them that ambition and those arts of rising, which,
put in practice, have steeled their hearts against filial piety, as well
as the other affections that belong not to calculation. Since the
paramount object of your training was to teach them to shine, and
make the most out of every body, you have at least a right to expect
from their vanity, pompous funeral solemnities. I revere that
indication of infinite wisdom, that has rendered the love of the
parent more anxious and tender than that of the child. The intensity
of the affections ought to be proportionate to the wants of the
beings that excite them. But ingratitude is not in nature. Better
training would have produced other manners. In rearing our children
with more enlightened care, in inspiring them with moderate desires,
in reducing their eagerness for brilliancy and distinction, we shall
render them happy, without stifling their natural filial sentiments;
and we shall thus use the best means of training them to sustain
and soothe our last moments, as we embellished their first days.[34]](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-34-320.jpg)
![L E T T E R X V I .
O F F R I E N D S H I P.
Let us bring within the family circle a few persons of amiable
manners and simple tastes. Our domestic retreat may then become
our universe. But we must search for real friends, with capabilities
for continuing such. If interest and pleasure break the accidental ties
of a day, shall friendship, which was always a stranger to the
connexion, be accused of the infraction?
A real friend must not be expected from the common ties of
vulgar interest; but must be, in the circle to which he belongs, as a
brother of adoption. So simple should be our confidence in the
entireness of his affection, and the disinterestedness and wisdom of
his advice, as to incline us to consult him without afflicting our wife
or children by a useless communication of our perplexities. To him
we should be able to confide our fears; and while we struggle, by his
advice and aid to escape the pressing evil which menaces to
overwhelm us, our family may still repose in tranquil security.[35]
If he suffer in turn, we share his pains. If he have pleasures, we
reciprocally enjoy them. If either party experience reverses, instead
of finding himself alone in misery, he receives consolations so
touching and tender, that he ceases to complain of a lot which has
enabled him to become acquainted with the depth of the resources
of friendship.
How pure is the sentiment, how simple the pleasures, which flow
from the intercourse of two men united by similar opinions and like
desires, who have both cultivated letters, the arts, and true wisdom!
With what rapidity the moments of these charming conversations fly!
Even the hours consecrated to study are less pleasant, perhaps less
instructive. Such a friend, so to speak, is of a different nature from
that of the rest of men. They either conceal our defects, or cause us
to see them from motives of ill feeling. A friend so discusses them, in](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-36-320.jpg)
![extent of his fortune? ‘Mine is small,’ he replied, ‘but my friend is
rich.’ The other, a few days before he died of a contagious disease,
asked, ‘why so many persons were allowed to enter his chamber? No
one,’ he added, ‘ought to be admitted but my friend.’ Thus were they
one in fortune, in life and in death.[36]
I deem, that even moralists have sought to render this peaceable
sentiment, this gentle affection, and the only one exempt from
storms, too exclusive. I am aware, how much our affections become
enfeebled, in proportion as their objects multiply. There is force in
the quaint expression of an old author. ‘Love is like a large stream
which bears heavy laden boats. Divide it into many channels, and
they run aground.’ Still, we may give the honored name of friend to
several, without profaning it, if there exist between us mutual
sympathy, high esteem and tender interest; if our pleasures and
pains are, in some sense, common stock, and we are reciprocally
capable of a sincere devotion to each other’s welfare. As much,
however, as I revere the real sentiment, I am disgusted by the sickly
or exaggerated affectation of it.
The sentiment is still more delightful when inspired by a woman. I
shall be asked, if it can exist in its purity between persons of the
different sexes? I answer in the affirmative, when the impulses of
youth no longer agitate the heart. We then experience the whole
charm of the sentiment, as the difference of sex, which is never
entirely forgotten, imparts to it a vague and touching tenderness and
an ideal delight for which language is too poor to furnish terms.
Why can love and friendship, the sunshine of existence, decay in
the heart? Why are they not eternal? But since it is not so, if we are
cruelly deceived in our affections, the surest means of medicating
our pain is, instead of cherishing misanthropic distrust, to look round
and form the same generous ties anew. Has your friend abandoned
you? or, worse, has your wife become unworthy of your love? It is
better to be deceived a thousand times than to add, to the grief of
wounded affection, the insupportable burden of general distrust,
misanthropy and hatred. Let these baneful feelings never usurp the](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-38-320.jpg)
![place of those sentiments which must constitute human happiness.
Pardon to those by whom you have been loved, the sorrows which
their abandonment has caused you, in consideration of those days of
the past which was embellished by their friendship.
But these treasons and perfidies are only frequent in the
intercourse of those who are driven about by the whirlwinds of life;
in which so many opposing interests, so many deceitful pleasures
confuse and separate men. The simple minded and good, whose
days flow pleasantly in retreat, every day value more the price of
those ties that unite them. Their happiness is veiled and guarantied
by a guardian obscurity.
I give place to none of the illusions of inexperience in regard to
men.[37] The errors, contradictions and vices with which they are
charged, exist. I admit that the greater part of satires are faithful
paintings. But there are still to be found, everywhere, persons whose
manners are frank, whose heart is good, and whose temper amiable.
These persons exist in sufficient numbers to compose this new world
of which I have spoken. Writers are disposed to declaim against
men. I have never ceased to feel good will towards my kind. I have
chosen only to withdraw from the multitude, in order to select my
position in the centre of a small society. For me there are no longer
stupid or wicked people on the earth.
I have examined the essential things of life, tranquillity and
independence of mind, health, competence and the affection of
some of our kind. I wish now to give my observations something
more of detail and diversity. But I wish it still to be borne in mind,
that I give only the materials and outlines of an essay, and make no
pretensions to fill out a complete treatise. I wish that a temple may
be raised to happiness. Hands, more skilful than mine, will rear it. It
is sufficient to my purpose to indicate those delightful sites, in the
midst of which it may be erected.](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-39-320.jpg)
![L E T T E R X V I I .
T H E P L E A S U R E S O F T H E S E N S E S .
Nature has decreed, that each one of our senses should be a
source of pleasure. But if we seek our enjoyment, only in physical
sensations, the same stern arbiter has enacted, that our capability of
pleasure should soon be exhausted, and that, palled and disgusted,
we should die without having known true happiness.[38]
Exactly in proportion as pleasures are less associated with the
mind, their power to give us any permanent satisfaction is
diminished. On the contrary, they become vivid and durable,
precisely in the degree in which they awaken and call forth moral
ideas. They become celestial, when they connect the past with the
present, the present with the future, and the whole with heaven.
In proportion as we scrutinize the pleasures of the senses, we
shall always find their charm increasing in the same degree, as
losing, if I may so say, their physical stain, they rise in the scale of
purification, and become transformed, in some sense, to the dignity
of moral enjoyments.
I look at a painting: it represents an old man, a child, a woman
giving alms, and a soldier, whose attitude expresses astonishment. I
admire the fidelity, the truth and coloring of the picture; and my eye
is intensely gratified. But remaining ignorant of the subject, I go
away, and the whole shortly vanishes from my memory. I see it
again; and am now struck with the inscription at the bottom, ‘Date
obolum Belisario.’ I remember an interesting passage of history. A
crowd of moral images throng upon my spirit: I soften to
tenderness; and I comprehend the affecting lesson, which the artist
is giving me. I review the painting, again and again; and thrill at the
view of the blind warrior, and of the child holding out his helmet to
receive alms.](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-41-320.jpg)
![When we travel, those points of view in the landscape which long
fix our eye, are those which awaken ideas of innocence and peace;
affecting the heart with associations connected with the morning of
our life; or ideas of that power and immensity, which move and
elevate the soul. The paintings of nature, as well as those of men,
are thus capable of being embellished by moral associations. In
travelling, I perceive a delightful isle embosomed in a peaceful lake.
While I contemplate it, with the simple pleasure excited by a
charming landscape, I am told that it is inhabited by a happy pair,
who were long crossed and separated; but who wore out the
persevering opposition of fortune; and are now living there in the
innocence and peace of the first tenants of paradise. How different
an interest the landscape now assumes! I behold the happy pair,
without care or regret, sheltered from jealous observation, enjoying
the dream of their happy love, gratefully contemplating the Author
of the beautiful nature around them, and elevating their love and
their hearts, as a sacrifice to HIM.
Sites, which, in themselves, have no peculiar charm, become most
beautiful as soon as they awaken touching remembrances. Suppose
yourself cast by misfortune on the care of a stranger in a strange
land. He attempts to dispel your dejection, and says, ‘these countries
are hospitable, and nature here puts forth all her opulence; come,
and enjoy it with us.’ The gay landscapes, which spread before you,
all assume the appearance of strangers; and offer no attractions. But
while your eye traverses the scenery with indifference, you see blue
hills melting into the distant horizon. No person remarks them, but
yourself. They resemble the mountains of your own country, the
scenes upon which your infant view first rested. You turn away to
conceal the new emotions, and your eyes are filling with tears. You
continue to gaze fondly on those hills, dear to memory. In the midst
of a rich landscape, they are all that interests you. You return to
review them every day, and demand of them their treasured
remembrances and illusions,—the dearest pleasures of your exile.[39]](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-42-320.jpg)
![physical sensations. An embalmed atmosphere exalts the senses,
and disposes the mind to pleasant revery, and paints dreams of
paradise upon the indolent imagination.
Were I disposed to present the details of a system upon this
subject, the sense of hearing would offer me a crowd of examples.
The brilliant and varied accents of the nightingale are ravishing. But
what a difference between hearing the melody from a cage, and
listening to the song at the noon of night, when a cool and pure air
refreshes the lassitude of the burning day, and we behold objects by
the light of the moon, and hear the strains of the solitary bird
poured from her free bower!
A symphony, the sounds of which only delight the ear, would soon
become wearying. If it have no other determinate expression, it
ought, at least, to inspire revery, and produce an effect not unlike
that of perfumes upon the orientals.
Suppose we have been at an opera, got up with all the luxury of
art. Emotions of delight and astonishment rapidly succeed each
other, and we believe it impossible to experience new sensations of
pleasure. In returning home, we chance to hear in the distance,
through the stillness of night, a well remembered song of our
infancy, that was sung to us by some one dear to our memory. It is
at once a music exciting more profound emotion, than all the strains
of art which we so recently thought could not be surpassed. The
remembrances of infancy and home rush upon the spirit, and efface
the pompous spectacle, and the artificial graces of execution.[39a]
Observations to the same effect might be multiplied without end.
If you desire pleasures, fertile in happy remembrances, if you wish
to preserve elevation of mind and freshness of imagination, choose,
among the pleasures of the senses, only those which associate with
moral ideas. Feeble, when separated from the alliance of those
ideas, they become fatal when they exclude them. To dare to taste
them, is to sacrifice happiness to pleasures which are alike
ephemeral and degrading. It is to resemble him, who should strip
the tree of its flowers, to enjoy their beauty. He loses the fruits](https://image.slidesharecdn.com/40177-250630030436-d6c8b220/85/Electrophysiology-Basics-Methods-Modern-Approaches-and-Applications-Jurgen-Rettinger-44-320.jpg)
Electrophysiology Basics Methods Modern Approaches and Applications Jürgen Rettinger
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- 5. Electro- physiology Basics, Methods, Modern Approaches and Applications SecondEdition Jürgen Rettinger Silvia Schwarz Wolfgang Schwarz
- 7. Jürgen Rettinger • Silvia Schwarz • Wolfgang Schwarz Electrophysiology Basics, Methods, Modern Approaches and Applications Second Edition
- 8. Jürgen Rettinger Tübingen, Baden-Württemberg Germany Silvia Schwarz Shanghai University of Traditional Chinese Medicine Shanghai Research Center for Acupuncture and Meridians Shanghai, China Wolfgang Schwarz Institute for Biophysics Goethe University Frankfurt, Hessen Germany ISBN 978-3-030-86481-1 ISBN 978-3-030-86482-8 (eBook) https://doi.org/10.1007/978-3-030-86482-8 # The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2016, 2022 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland
- 9. Preface This book is based on the previous versions by J. Rettinger, S. Schwarz, and W. Schwarz entitled Electrophysiology and Elektrophysiologie, which form the basis for lectures on Electrophysiology held at Goethe-University Frankfurt, Chinese Academy of Sciences (Shanghai), and Fudan University Shanghai. This new second edition of the English version is again addressed to students of biology, chemistry, and physics with special interest in biophysics. Because of the heterogeneity of the addressed readers, we will try to give basic information on physical as well as biological background but not more than necessary. Tübingen, Baden-Württemberg, Germany Jürgen Rettinger Shanghai, China Silvia Schwarz Frankfurt am Main, Hessen, Germany Wolfgang Schwarz June 2021 v
- 10. Acknowledgements We would like to express our thanks to Prof. Guanghong Ding and Prof. Dr. Di Zhang from Fudan University Shanghai and to Prof. Dr. Werner Mäntele and Dr. Georg Wille from Goethe University Frankfurt for their continuous support in having Electrophysiology a part of education in Biophysics at the two universities. This was and still is the basis for this book. vii
- 11. About This Book After a brief introductory and historical overview on electrophysiology (see Chap. 1), basic electrochemical principles for the understanding of this subject are summarised (see Chap. 2). Thereafter, electrophysiological methods including principles of data analysis are presented in Chap. 3 ranging from measurements on the whole animal via measurements on single cells with microelectrodes to the patch-clamp technique. This chapter also includes a brief presentation of ion-selective microelectrodes, the carbon-fibre technique, and the sniffer-patch method. The basic method in electrophysiology is the voltage-clamp technique (see Chap. 4), and different ways of applying the voltage clamp are described. The chapter deals with different versions of the conventional two-microelectrode technique, the patch-clamp technique, and examples for automated electrophysiology. In Chap. 5, the major conductance pathways in cell membranes, the ion-selective channels, are described with respect to their specific characteristics. Essentials of membrane excitability based on Hodgkin-Huxley description of an action potential and synaptic transmission are presented in Chap. 6. The sensitivity of modern voltage-clamp techniques allows detection of carrier-mediated transport, and Chap. 7 presents by means of three examples characteristics of carriers compared to channels and how electrophysio- logical methods can be used for functional characterisation. Finally, in Chap. 8 we finish with exemplary illustrations of how combination of electrophysiology, molecular biology, and pharmacology can be applied to learn about the structure, function, and regulation of membrane permeabilities that form the basis of cellular function and how they are involved in diseases. In addition to the Na,K pump and the GABA transporter, as examples for active transporters, the purinergic receptor P2X and viral ion channels are introduced as examples for ion channels. A special section illustrates how electrophysiology can be used to understand basic cellular mechanisms in Chinese medicine and to investigate drug-receptor interaction in pharmacology. Each chapter is completed by a “Take-Home Messages” table and a set of exercises for recalling important topics. The book is supplemented by appendices (Chap. 9) describing the influence of electrical and magnetic fields on physiological function and a manual for a Laboratory Course in electrophysiology using the two-electrode voltage clamp. ix
- 12. Important Physical Units In the following we will list important electrical quantities and their usual definitions. Voltage U [Volt, V]: 1 V is the difference in electric potential between two points of a conductor carrying a constant cur- rent of 1 A, when the power dissipated between those points is equal to 1 W. Resistance R [Ohm, Ω]: 1 Ω is the resistance of a conductor such that a constant current of 1 A produces a voltage drop of 1 V between its ends. Conductance g [Siemens, S]: The inverse of the resistance R. Current I [Ampere, A]: 1 A is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross section, and placed one metre apart in a vacuum, would produce between these conductors a force equal to 2 107 Newton per 1 m of length. Charge Q [Coulomb, C]: 1 Coulomb equals the charge of 6.25 1018 ele- mentary charges e. Capacitance C [Farad, F]: 1 F is the capacitance of a capacitor between the plates of which there appears a difference of poten- tial of 1 volt when it is charged by a quantity of charge equal to 1 coulomb. Magnetic Flux Density B [Tesla, T]: 1 T is the density of a homogenous magnetic flux of 1 Weber (Wb) perpendicular to an area of 1 m2 : 1T ¼ 1 Wb/m2 . Volt: V ¼ W A ¼ kgm2 As3 Ohm: Ω ¼ V A ¼ kgm2 A2 s3 Siemens: S ¼ 1 Ω ¼ A2 s3 kgm2 xi
- 13. Current: A ¼ A Coulomb: C ¼ A s Farad: F ¼ C V ¼ A2 s4 kgm2 The quantities listed above can be also expressed in terms of SI units (metre, kilogram, second, Ampere). Note: Only charge and current are expressed in terms of SI units (A and s). xii Important Physical Units
- 14. Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Basic Background Knowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 History of Electrophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2 Basics Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.1 Electrical Characteristics of Biological Membranes . . . . . . . . . . . . . . . 13 2.2 Ion Distribution at Biological Membranes . . . . . . . . . . . . . . . . . . . . . . 15 2.3 Donnan Distribution and Nernst Equation . . . . . . . . . . . . . . . . . . . . . . 16 2.3.1 Donnan Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2.3.2 Nernst Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.4 Goldman–Hodgkin–Katz Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3 Basics: Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.1 Recording Electrical Signals from Body Surface . . . . . . . . . . . . . . . . . 28 3.2 The Example (ECG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.2.1 Electrophysiological Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.2.2 Activation of the Heart Muscle . . . . . . . . . . . . . . . . . . . . . . . . 33 3.3 Recording Electrical Signals from Tissue . . . . . . . . . . . . . . . . . . . . . . . 35 3.3.1 Intracardiac Electrograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.3.2 The Ussing Chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.3.3 Recording from the Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3.3.4 Recording Extracellular Field Potentials with Multielectrode Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.4 Recording Electrical Signals from Single Cells . . . . . . . . . . . . . . . . . . 38 3.4.1 The Ag/AgCl Electrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 3.4.2 The Microelectrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3.4.3 Ion-Selective Microelectrodes . . . . . . . . . . . . . . . . . . . . . . . . . 40 3.4.4 The Carbon-Fibre Technique . . . . . . . . . . . . . . . . . . . . . . . . . . 43 3.4.5 Basics of Voltage Clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 xiii
- 15. 3.4.6 Noise in Electrophysiological Measurements . . . . . . . . . . . . . . 52 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 4 Application of the Voltage-Clamp Technique . . . . . . . . . . . . . . . . . . . . . . 61 4.1 Different Versions of the Voltage-Clamp Technique . . . . . . . . . . . . . . 62 4.1.1 The Classic Squid Giant Axon . . . . . . . . . . . . . . . . . . . . . . . . . 62 4.1.2 The Vaseline- or Sucrose-Gap Voltage Clamp . . . . . . . . . . . . . 62 4.1.3 The Two-Microelectrode Voltage Clamp . . . . . . . . . . . . . . . . . 63 4.1.4 The One-Electrode Voltage Clamp . . . . . . . . . . . . . . . . . . . . . . 65 4.1.5 The Open-Oocyte Voltage Clamp . . . . . . . . . . . . . . . . . . . . . . 66 4.2 Analysing Current Fluctuations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 4.3 Analysing Transient Charge Movements (Gating Currents) . . . . . . . . . . 68 4.4 The Patch-Clamp Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 4.4.1 Different Versions of Patch Clamp (Patch Conformations) . . . . . 71 4.4.2 Advantages of the Different Patch Conformations . . . . . . . . . . . 72 4.4.3 The Single-Channel Current and Conductance . . . . . . . . . . . . . 74 4.4.4 The Sniffer-Patch Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 4.5 Automated Electrophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 4.5.1 Automated Patch Clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 5 Ion-Selective Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 5.1 General Characteristics of Ion Channels . . . . . . . . . . . . . . . . . . . . . . . 86 5.1.1 Selectivity of Ion Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 5.1.2 Discrete Movement of Ions through Pores . . . . . . . . . . . . . . . . 89 5.2 Specific Ion Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 5.2.1 The Na+ Channel (A Single-Ion Pore) . . . . . . . . . . . . . . . . . . . 91 5.2.2 The K+ Channel (A Multi-Ion Pore) . . . . . . . . . . . . . . . . . . . . . 93 5.2.3 The Ca2+ Channel (A Multi-Ion Pore) . . . . . . . . . . . . . . . . . . . 95 5.2.4 Anion-Selective Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 6 Theory of Excitability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 6.1 The Hodgkin–Huxley Description of Excitation . . . . . . . . . . . . . . . . . . 102 6.1.1 Experimental Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 6.1.2 The Hodgkin–Huxley (HH) Description of Excitability . . . . . . . 105 6.1.3 The Action Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 6.2 Continuous and Saltatory Spread of Action Potentials . . . . . . . . . . . . . 113 6.2.1 The Electrotonic Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 6.2.2 The Continuous Spread of an Action Potential . . . . . . . . . . . . . 117 6.2.3 The Saltatory Spread of an Action Potential . . . . . . . . . . . . . . . 118 6.3 Generation and Transmission of Action Potentials . . . . . . . . . . . . . . . . 119 6.3.1 Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 xiv Contents
- 16. 6.3.2 Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 6.4 Summary of the Different Types of Potentials . . . . . . . . . . . . . . . . . . . 121 6.4.1 Surface Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 6.5 Action Potential in Non-nerve Cells . . . . . . . . . . . . . . . . . . . . . . . . . . 122 6.5.1 Skeletal Muscle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 6.5.2 Smooth Muscle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 6.5.3 Heart Muscle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 6.5.4 Plant Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 7 Carrier-Mediated Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 7.1 General Characteristics of Carriers . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 7.1.1 Distinction Between Pores and Carriers . . . . . . . . . . . . . . . . . . 130 7.1.2 The Oocytes of Xenopus: A Model System . . . . . . . . . . . . . . . . 132 7.1.3 The Anion Exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 7.1.4 The Sodium Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 7.1.5 The Neurotransmitter Transporter GAT1 . . . . . . . . . . . . . . . . . 139 7.2 Carriers Are Like Channels with Alternating Gates . . . . . . . . . . . . . . . 141 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 8 Examples of Application of the Voltage-Clamp Technique . . . . . . . . . . . . 147 8.1 Structure–Function Relationships of Carrier Proteins . . . . . . . . . . . . . . 150 8.1.1 The Na+ ,K+ -ATPase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 8.1.2 The Na+ -Dependent GABA Transporter (GAT1) . . . . . . . . . . . . 152 8.2 Structure–Function Relationships of Ion Channels . . . . . . . . . . . . . . . . 152 8.2.1 Families of Various Ion Channels . . . . . . . . . . . . . . . . . . . . . . 152 8.2.2 ATP-Gated Cation Channel (ACC) Family . . . . . . . . . . . . . . . . 156 8.2.3 Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 8.3 Viral Ion Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 8.3.1 The 3a Protein of SARS Coronavirus . . . . . . . . . . . . . . . . . . . . 164 8.3.2 Channel Proteins of SARS Coronavirus-2 . . . . . . . . . . . . . . . . . 167 8.3.3 The Viral Protein Unit (Vpu) of HIV-1 . . . . . . . . . . . . . . . . . . . 168 8.3.4 The M2 (Matrix Protein 2) of Influenza a Virus . . . . . . . . . . . . 170 8.4 Electrophysiology as a Tool in Chinese Medicine Research . . . . . . . . . 171 8.4.1 Mechanisms in Acupuncture Points . . . . . . . . . . . . . . . . . . . . . 173 8.4.2 Mechanisms in Effected Sites . . . . . . . . . . . . . . . . . . . . . . . . . 174 8.5 Electrophysiology as a Tool in Pharmacology . . . . . . . . . . . . . . . . . . . 176 8.5.1 The Na+ ,Ca2+ Exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 8.5.2 Neurotransmitter Transporters . . . . . . . . . . . . . . . . . . . . . . . . . 178 8.5.3 Ion Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Contents xv
- 17. 9 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 9.1 Influence of External Electrical and Magnetic Fields on Physiological Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 9.1.1 Magnetostatic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 9.1.2 Electrostatic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 9.1.3 Electromagnetic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 9.2 A Laboratory Course: Two-Electrode Voltage Clamp (TEVC) . . . . . . . 193 9.2.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 9.2.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 9.2.3 Questions to Be Answered for the Course . . . . . . . . . . . . . . . . . 198 9.2.4 Set-up and Basic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . 198 9.2.5 Experiments and Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . 200 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 xvi Contents
- 18. About the Authors Jürgen Rettinger received his doctor degree in physics at Goethe University in Frankfurt in 1995. His focus as group leader at Max-Planck-Institute of Biophysics in Frankfurt was research of structure-function relationships of ligand-gated ion channels and teaching electrophysiology at Goethe-University Frankfurt, Shanghai Institutes for Biological Sciences, and Fudan University Shanghai. Between 2008 and 2021 Jürgen Rettinger worked with Multi Channel Systems responsible as product manager for automated electrophysiology. Silvia Schwarz finished her university education in biology and chemistry at Albert- Ludwigs-University Freiburg in 1974. Thereafter, she was educated and worked as teacher in biology and chemistry until 2008. Since then she works as research associate at Shanghai Research Center for Acupuncture and Meridians (Shanghai Key Laboratory of Acupunc- ture Mechanism and Acupoint Function, Fudan Univ.). Silvia Schwarz’s main research focus is on antiviral effects of Chinese herbal drugs applying electrophysiological methods. Wolfgang Schwarz received his doctor degree in physics at the University of Saarland in 1975. Thereafter, he spent two years as postdoc at the University of Washington Seattle working on characteristics of ion channels. In 1981 he habilitated in physiology at the University of Saarland and received a position as head of a Cell Physiology Laboratory at Max-Planck-Institute of Biophysics, Frankfurt. Wolfgang Schwarz’s main focus turned to structure-function and regulation of carrier transporters and teaching electrophysiology as professor for physics at Goethe-University Frankfurt, Shanghai Institutes for Biological Sciences, and Fudan University Shanghai. Since 2004 Wolfgang Schwarz is head of the Cell Electrophysiology Laboratory of Shanghai Research Center for Acupuncture and Meridian (Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, Fudan Univ.) and concurrent professor at Fudan University. xvii
- 19. Abbreviations γ Single-channel conductance, activity coefficient δ Quantisation step, charge density ε0 Polarisability of free space η Viscosity λ Length constant μ (Electro)chemical potential ρ Specific resistance τ Time constant a Activity A Gain (op-amplifier), area ASM Airway smooth muscle AU Arbitrary unit au Arbitrary units B Bandwidth C Capacitance c Concentration Ca2+ i Intracellular calcium activity CypA Cyclophilin A D Diffusion coefficient, dissipation factor (capacitor) DOR δ-opioid receptor DPDPE [D-Pen2 ,D-Pen5 ]enkephalin e Elementary charge E, V, Φ Electric potential EAAC Excitatory amino acid carrier EC ()-epicatechin EGCG ()-epigallocatechin-3-gallate F Faraday’s constant f Frequency FBA Feedback amplifier G Gibb’s energy GA Glycyrrhizic acid xix
- 20. Another Random Scribd Document with Unrelated Content
- 21. L E T T E R X I V. O F M A R R I A G E . Since we cannot assure ourselves of the general affection, nor even of the justice of men, it becomes our interest, in the midst of the great mass, that we cannot move, to create a little world, which we can arrange at the disposal of our reason and affections. In this retreat, dictated to us alike by our instincts and our hearts, let us forget the chimeras which the crowd pursue; and if the men of fashion and the world stare, ridicule, and even condemn us, let their murmurs sound in our ears as the dashing of the waves on the distant shore, to the stranger, under the hospitable roof which shelters him from the storm. The universe of reason and affection must be composed of a single family. Of that universe a wedded pair must be the centre. A wife is the best and the only disinterested friend, by the award of nature. She remains such, when fortune has scattered all others. How many have been recalled to hope by a virtuous and affectionate wife, when all beside had been lost! How many, retrieved from utter despondency, have felt in an ineffable effusion of heart, that conjugal heroism and constancy were an ample indemnity for the deprivation of all other good things! How many, undeceived by external illusions, have in this way been brought home to their real good! If we wish to see the attributes of conjugal heroism, in their purest brilliancy, let us suppose the husband in the last degree of wretchedness. Let us imagine him not only culpable, but so estimated, and an outcast from society. Repentance itself, in the view of candor, has not been available to cloak his faults. She alone, accusing him not, is only prodigal of consolations. Embracing duties as severe as his reverses, she voluntarily shares his captivity or exile. He finds still, on the faithful bosom of innocence, a refuge, where
- 22. remorse becomes appeased; as in former days, the proscribed found, at the foot of the altar, an asylum against the fury of men. Marriage is generally assumed as a means of increasing credit and fortune, and of assuring success in the world. It should be undertaken as a chief element of happiness, in the retirement of domestic repose.[28] I would wish that my disciple, while still in the freshness of youth, might have reason and experience enough to select the beloved person, whom he would desire one day to espouse. I would hope, that, captivated with her dawning qualities, and earnestly seeking her happiness, he might win her tenderness, and find his satisfaction in training her to a conformity to his tastes, habits and character. The freshness of her docile nature demands his first forming cares. As she advances in life she is moulded to happy changes, adapted to supply his defects. She is reared modest, amiable, instructed, respectable, and respected; one day to govern his family, and direct his house, by diffusing around the domestic domain, order and peace. Let neither romances, metaphysics, pedantry nor fashion render a qualification for these important duties, either trifling or vulgar in her view. Still, domestic duties are by no means to occupy all her hours. The time which is not devoted to them will flow quietly on in friendly circles, not numerous, but animated by gayety, friendship and the inexplicable pleasures which spring from intercourse with rational society. There are, also, more unimportant duties, which we expect her not to neglect. We wish her to occupy some moments at a toilet; where simplicity should be the basis of elegance; and where native tact might develope the graces, and vary, and multiply, if I may so say, the forms of her beauty. In fine, the versatility of her modes of rendering herself agreeable, should increase the chances of always escaping ennui in her presence. But train women to visit a library as savans, and they will be likely to bring from it pedantry without solid instruction; and coquetry without feminine amiability. I would not be understood to question the capability of the female understanding. I am not sure that I
- 23. would wish the wife of my friend to have been an author, though some of the most amiable and enlightened women have been such. But I deem that in their mental constitution, and in the assignment of their lot, providence has designated them to prefer the graces to erudition; and that to acquire a wreath of laurels, they must ordinarily relinquish their native crown of roses.[28a] When we see a husband and wife thus united by tenderness, good hearts and simple tastes, everything presages for them a delightful futurity. Let them live contented in their retirement. Instead of wishing to blazon, let them conceal their happiness, and exist for each other. Life will become to them the happiest of dreams. Perhaps the world will say, ‘you speak, it may be, of such a wife as you would be understood to possess yourself. But you do not paint marriage in the abstract, while you thus describe happiness as finding a habitation within the domestic walls, and pain and sorrow without: how many people find eternal ennui at home, and respire pleasure, only when they have fled their own threshold.’ There are few wives so perfect, says La Bruyere, ‘as to hinder their husbands from repenting at least once in a day, that they have a wife; or from envying the happiness of him who has none.’ This sentence, instead of containing a just observation, is only an epigram. In looking round a circle of individuals, ridiculously called the world, we shall find happy family establishments less rare than we imagine. Besides, it would be absurd to count among unhappy unions, all those which are not wholly exempt from stormy passions. Not only is perfect felicity a chimerical expectation on the earth, but we meet with many people who would be fatigued into ennui in a perfect calm, and who require a little of the spice of contrariety to season the repast of life. I would not covet their taste; but there are modes of being singular, which, without imparting happiness, procure pleasures. Finally, supposing the number of unhappy marriages to be as immense as is contended, what is the conclusion? The great majority adopting, as maxims of life, principles
- 24. so different from mine, it would be strange if they obtained such results as I desire. In these days, the deciding motive with parents, in relation to marriage, is interest; and, what seems to me revolting in the spirit of the age, is, that the young have also learned to calculate. When a man marries simply on a speculation of interest, if he sees his fortune and distinction secured, reign disorder and alienation in his house as they may, he is still happier than he deserves to be. Our marriages of inclination guaranty happiness no more than our marriages of interest. What results should be anticipated from the blind impulse of appetite? Let there be mutual affection, such as reason can survey with a calm and severe scrutiny. Such love as is painted in romances is but a fatal fever. It is children alone who believe themselves in love, only when they feel themselves in a delirium. They have imagined that life should be a continual ecstasy; and these indulged dreams of anticipation spoil the reality of wedded life. I have supposed the husband older than his wife. I have imagined him forming the character of his young, fair and docile companion; and that, so to speak, they have become assimilated to each other’s tastes and habits. The right combination of reason and love assures for them, under such circumstances, as much as possible, a futurity of happiness. I might here speak of the misery of jealousy and infidelity, and the comparative guilt of these vices in the husband and the wife. But these are sources of torment only in unions contracted and sustained by the maxims and the spirit of the world. According to my views these crimes could not mar the marriages which were undertaken from right motives, and under the approving sanction of severe reason. I, therefore, pass them by, as not belonging to my subject; and as supposing that when marriage is the result of wise foresight and regulated choice, and when its duties are discharged from a proper sense of their obligation, such faults can not occur. Another cause of disunion springs from the proud temper of some wives. They erroneously and obstinately persuade themselves that
- 25. fidelity includes all their duty. More than one husband, incessantly tormented by an imperious and capricious wife, feels almost disposed to envy the gentle spouse who sleeps pleasantly under deceitful caresses. As much as an honest man ought to avoid crimes, in order to merit his reputation and sustain it, ought the highest meed awarded to women to be bestowed, not on those alone who are chaste, but on those who know how to watch over the happiness of their family by eager attentions and studious cares. This petulance of temper is commonly supposed to be a conjoined attribute of conjugal fidelity. I have sometimes seen wives both peevish and coquettish, and I cannot imagine a more odious combination. If we despise the man who is rough and slovenly at home, and becomes charming in society, what sentiment does that wife merit who wears out her husband’s patience with her arrogance, and puts on seducing graces, and affects sensibility, in the presence of strangers? I have often heard men who were sensible upon every other subject, express their conviction that the orientals, in excluding their women from all eyes but their own, had established the only reasonable domestic policy. There is no more wit than humanity in this barbarous sentiment, however frequently it is uttered. No one could be in earnest, in wishing to copy, into free institutions, this appalling vestige of slavery. But my inward respect for women withholds me from flattering them. Authority ought to belong to the husband; and the influence of tenderness, graces and the charms of constancy, gentleness and truth, constituting the appropriate female empire, belongs of right to the wife. I take leave to illustrate this phrase. Masculine vigor, and aptitude to contend and resist, clearly indicate that nature has confided authority to man. To dispossess him of it, and control him by a still more irresistible sway, it is necessary that the feeble sex should learn patience, docility, passive courage, and the management of their appropriate weapons in danger and sorrow, and to become energetic for the endurance of the peaceful cares of the domestic establishment. Man is formed by nature for the calls of active courage; and woman, for the appalling
- 26. scenes of pain and affliction, and the agony of the sick and dying bed. In a word, all argument apart, nature has clearly demonstrated to which sex authority belongs. I discover that the defects of man spring from the tendency of his natural traits, in which force predominates, to run to excess. I see his gentle companion endowed with attributes and qualities naturally tending to temper his defects. The means she has received to reach this end announce that it is the purpose of nature that she should use them with this view. She has charms which, when rightly applied, none can resist. Her character is a happy compound of sensibility, wisdom and levity. She has superadded a felicity of address which she owes to her organization, and which the reserve, that her education imposes, serves to develope. Thus the qualities, and even the imperfections of the two sexes serve to bring them together. It follows, that man should possess authority, and woman influence, for their mutual happiness. When the wife commands, I cease to behold a respectable married pair. I see a ridiculous tyrant, and a still more ridiculous slave. It is vain to urge that she may be most capable of authority, and that her orders may be conformable to wisdom and justice. They are absurd, from the very circumstance that they are orders. The virtues which the husband ought to practise towards his wife must have their origin in love, which can only be inspired, and which flies all restraint. In a single position, the wife honors herself in assuming authority. It is when reverses have overwhelmed and desolated her husband, so that, ceasing to sustain her and changing the natural order, she supports him. Grant that he receives hope as her gift; grant that he is compelled to blush in imitating her example of courage; she aspires to this power no longer than to be able to restore him to the place whence misery had cast him down.[30] It is a truth that ought not to be contested, that dissatisfied husbands and wives often love each other more than they imagine. Suppose them to believe themselves indifferent; and to seem so; and even on the verge of mutual hate; should one of them fall sick,
- 27. we see the other inspired with sincere alarms. Suppose them on the eve of separation; when the fatal moment comes, both recoil from the act. Habit almost causes the pains, to which we have been long accustomed, to become cause of regret when they cease. When the two begin mutually to complain of their destiny, I counsel each, instead of wishing to criminate and correct each other, to give each other an example of mutual forbearance and indulgence. It may be, that the cause of their mutual dissatisfaction is unreal; the supposed wrong not intended, the suspicion false. Candor and forgiveness will appease all. The husband may have gone astray only in thought; which is beyond human privilege to fathom. The wife may have minor defects and an unequal temper, without forfeiting much excellence and many remaining claims to be loved. The morbid influence of ill health and irresistible temperament, in their powerful action upon the temper, may have been the source whence the faults flowed on either part; and the mutual wrongs may thus have been, in some sense, independent of the will of the parties. Bound, as they are, in such intimate and almost indissoluble relations, before they give that happiness, which they hoped and promised, to the winds, let them exhaust their efforts of self-command and mutual indulgence, to bring back deep and true affection. The purest happiness of earth is, unquestionably, the portion of two beings wisely and fitly united in the bonds of indissoluble confidence and affection. What a touching picture does Madame de Stael present in these lines: ‘I saw, during my sojourn in England, a man of the highest merit united to a wife worthy of him. One day, as we were walking together, we met some of those people that the English call gipseys, who generally wander about in the woods in the most deplorable condition. I expressed pity for them thus enduring the union of all the physical evils of nature. “Had it been necessary,” said the affectionate husband, pointing to his wife, “in order to spend my life with her, that I should have passed thirty years in begging with them, we would still have been happy.” “Yes,” responded the wife, “the happiest of beings.”’
- 29. L E T T E R X V. C H I L D R E N . One of the happiest days, and, perhaps, the most beautiful of life, is when the birth of a child opens the heart of the parent to emotions, as yet, unknown.[31] Yet what torments are prepared by this epoch! What painful anxiety, what agonies their sufferings excite! What terror, when we fear for their infant life! These alarms terminate not with their early age. The inquietude with which their parents watch over their destiny fills every period of their life to their last sigh. The compensating satisfaction which they bring must be very vivid, since it counterbalances so many sufferings. In order to love them, we have no need to be convinced that they will respond to our cares, and one day repay them. If there be in the human heart one disinterested sentiment, it is parental love. Our tenderness for our children is independent of reflection. We love them because they are our children. Their existence makes a part of ours; or, rather, is more than ours. All that is either useful or pleasant to them, brings us a pure happiness, springing from their health, their gayety, their amusements. The chief end which we ought to propose to ourselves, in rearing them, is to train and dispose them so that they may wisely enjoy that existence which is accorded them. Of all the happy influences which can be brought to bear upon their mind and manners, none is more beneficial than the example of parental gentleness. The good Plutarch most eloquently advanced this doctrine in ancient time. Montaigne, Rousseau, M’Kenzie, and various writers of minor fame among the moderns, have reproduced his ideas, and, by their authority, have finally effected a happy revolution in education. I delight to trace the most important ideas thus reproduced by enlightened and noble minds in different ages. It is chiefly by
- 30. persevering in the system of the influence of gentleness that we may expect an ultimate melioration in the human character and condition. But scarcely has any such salutary change been effected, before minds, either superficial or soured, see only the inconveniences which accompany it; and, instead of evading or correcting them, would return to the point whence they started. We hear people regretting the decline of the severity of ancient education; and maintaining the wisdom of those contrarieties and vexations which children used to experience; ‘a fitting discipline of preparation,’ say they, ‘to prepare them for the sorrows of life.’ Would they, on the same principle, inflict bruises and contusions, to train them to the right endurance of those that carelessness or accident might bring? ‘It is an advantage,’ say they, ‘to put them to an apprenticeship of pain at the period when the sorrow it inflicts is light and transient.’ This mode of speaking, with many others of similar import, presents a combination of much error with some truth. The sufferings of childhood seem to us trifling and easy to endure, because time has interposed distance between them and us; and we have no fear of ever meeting them again. It does not cease to be a fact, that the child that passes a year under the discipline of the ferule of a severe master, is as unhappy as a man deprived a year of his liberty. The latter, in truth, has less reason to complain; since he ought to find, in the discipline of his reason, and his maturity and force of character, more powerful motives for patient endurance. Parents! Providence has placed the destiny of your children in your hands. When you thus sacrifice the present to an uncertain future, you ought to have strong proof that you will put at their disposal the means of indemnification. If the sacrifice of the present to the future were indispensable, I would not dissuade from it. But my conviction is, that the best means of preparing them for the future may be found in rendering them as happy as possible for the present. If it should be your severe trial to be deprived of them in their early days, you will, at least, have the consolation of being able to say, ‘I have rendered them happy during the short time they were confided
- 31. to me.’ Strive then, by gentleness, guided by wisdom and authority, to cast the sunshine of enjoyment upon the necessary toils and studies of the morning of their existence. It is the stern award of nature to bring them sorrows. Our task is to soothe them. I feel an interest when I see the child regret the trinket it has broken, or the bird it has reared. Nature in this way, gives them the first lessons of pain, and strengthens them to sustain the more bitter losses of maturer days. Let us prudently second the efforts of nature; and to console the weeping child, let us not attempt to change the course of these fugitive ideas, nor to efface the vexation by a pleasure. In unavoidable suffering let the dawning courage and reason find strength for endurance. Let us first share the regrets, and gently bring the sufferer to feel the inutility of tears. Let us accustom him not to throw away his strength in useless efforts; and let us form his mind to bear without a murmur the yoke of necessity. These maxims, I am aware, are directly against the spirit of modern education, which is almost entirely directed towards the views of ambition. But while I earnestly inculcate gentleness in parental discipline, I would not confound it with weakness. I disapprove that familiarity between parents and children which is unfavorable to subordination. Fashion is likely to introduce an injurious equality into this relation. I see the progress of this dangerous effeminacy with regret. The dress and expenditures which would formerly have supplied ten children, scarcely satisfy at present the caprices of one. This foolish complaisance of parents prepares, for the future husbands and wives, a task most difficult to fulfil. Let us not, by anticipating and preventing the wishes of children, teach them to be indolent in searching for their own pleasures. Their age is fertile in this species of invention. That they may be successful in seizing enjoyment, little more is requisite to be performed on our part than to break their chains. There are two fruitful sources of torments for children. One is, what the present day denominates politeness. It is revolting to me
- 32. to see children early trained to forego their delightful frankness and simplicity, and learning artificial manners. We wish them to become little personages; and we compel them to receive tiresome compliments, and to repeat insignificant formulas of common-place flattery. In this way, politeness, destined to impart amenity to life, becomes a source of vexation and restraint. It would seem as if we thought it so important a matter to teach the usages of society, that they could never be known unless the study were commenced in infancy. Besides, do we flatter ourselves, that we shall be able to teach children the modes and the vocabulary of politeness, without initiating them, at the same time, in the rudiments of falsehood? They are compelled to see that we consider it a trifle. If we wish them to become flatterers and dishonest, I ask what more efficient method we could take? Labor is the second source of their sufferings. I would by no means be understood to dissuade from the assiduous cultivation of habits of industry. You may enable children to remove mountains, if you will contrive to render their tasks a matter of amusement and interest. The extreme curiosity of children announces an instinctive desire for instruction. But instead of profiting by it, we adopt measures which tend to stifle it. We render their studies tiresome, and then say that the young naturally tire of study. When the parent is sufficiently enlightened to rear his child himself, instead of plying him with rudimental books, dictionaries and restraint, let him impart the first instructions by familiar conversation. Ideas advanced in this way are accommodated to the comprehension of the pupil, by mutual good feeling rendered attractive, and brought directly within the embrace of his mind. This instruction leads him to observe, and accustoms him to compare, reflect and discriminate, offers the sciences under interesting associations, and inspires a natural thirst for instruction. Of all results which education can produce, this is the most useful. A youth of fifteen, trained in this way, will come into possession of more truths, mixed with fewer errors, than much older persons reared in the common way. He will be distinguished by the early maturity of
- 33. his reason, and by his eagerness to cultivate the sciences, which, instead of producing fatigue or disgust, will every day give birth to new ideas and new pleasures. I am nevertheless little surprised, that the scrupulous advocates of the existing routine should insist that such a method tends to form superficial thinkers. I can only say to these profound panegyrists of the present order of instruction, that the method which I recommend, was that of the Greeks.—Their philosophers taught while walking in the shade of the portico or of trees, and were ignorant of the art of rendering study tiresome, and not disposed to throw over it the benefits of constraint. Modern instructers ought, therefore, to find that they were shallow reasoners, and that their poets and artists could have produced only crude and unfinished efforts.[33] Besides, this part of education is of trifling importance, compared with the paramount obligation to give the pupil robust health, pure morals, and an energetic mind. I deeply regret that the despotic empire of opinion is more powerful than paternal love. Instead of gravely teaching to your son the little arts of shining in the world, have the courage to say to him, ‘oblige those of thy kind whose sufferings thou canst lighten, and exhibit a constant and universal example of good morals. Form, every evening, projects necessary for enjoying a happy and useful succeeding day.’ Thus you will see him useful, good and happy, if not great in the world’s estimation. You will behold him peacefully descending the current of time. In striking the balance with life, he will be able to say, I have known only those sufferings which no wisdom could evade, and no efforts repel. But such are the prejudices of the age, to give such counsels to a son requires rare and heroic courage. Is not that filial ingratitude, of which parents so generally complain, the bitter fruit of their own training?—You fill their hearts with mercenary passions, and with measureless ambition. You break the tenderest ties, and send them to distant public schools. Your children, in turn, put your lessons to account, and abandon your importunate and declining age, if you depend on them, to mercenary
- 34. hands. When they were young, you ridiculed them out of their innocent recklessness, and frankness, and want of worldly wisdom. You vaunted to them that ambition and those arts of rising, which, put in practice, have steeled their hearts against filial piety, as well as the other affections that belong not to calculation. Since the paramount object of your training was to teach them to shine, and make the most out of every body, you have at least a right to expect from their vanity, pompous funeral solemnities. I revere that indication of infinite wisdom, that has rendered the love of the parent more anxious and tender than that of the child. The intensity of the affections ought to be proportionate to the wants of the beings that excite them. But ingratitude is not in nature. Better training would have produced other manners. In rearing our children with more enlightened care, in inspiring them with moderate desires, in reducing their eagerness for brilliancy and distinction, we shall render them happy, without stifling their natural filial sentiments; and we shall thus use the best means of training them to sustain and soothe our last moments, as we embellished their first days.[34]
- 36. L E T T E R X V I . O F F R I E N D S H I P. Let us bring within the family circle a few persons of amiable manners and simple tastes. Our domestic retreat may then become our universe. But we must search for real friends, with capabilities for continuing such. If interest and pleasure break the accidental ties of a day, shall friendship, which was always a stranger to the connexion, be accused of the infraction? A real friend must not be expected from the common ties of vulgar interest; but must be, in the circle to which he belongs, as a brother of adoption. So simple should be our confidence in the entireness of his affection, and the disinterestedness and wisdom of his advice, as to incline us to consult him without afflicting our wife or children by a useless communication of our perplexities. To him we should be able to confide our fears; and while we struggle, by his advice and aid to escape the pressing evil which menaces to overwhelm us, our family may still repose in tranquil security.[35] If he suffer in turn, we share his pains. If he have pleasures, we reciprocally enjoy them. If either party experience reverses, instead of finding himself alone in misery, he receives consolations so touching and tender, that he ceases to complain of a lot which has enabled him to become acquainted with the depth of the resources of friendship. How pure is the sentiment, how simple the pleasures, which flow from the intercourse of two men united by similar opinions and like desires, who have both cultivated letters, the arts, and true wisdom! With what rapidity the moments of these charming conversations fly! Even the hours consecrated to study are less pleasant, perhaps less instructive. Such a friend, so to speak, is of a different nature from that of the rest of men. They either conceal our defects, or cause us to see them from motives of ill feeling. A friend so discusses them, in
- 37. our presence, as not to wound us. He kindly reproaches us with faults, to our face, which he extenuates, or excuses before others in our absence. We can never fully comprehend to what extent a friend may be useful and dear until after having been a long time the faithful companion of his good and evil fortune. What emotions we experience in giving ourselves up to the remembrance of the common perils, storms and trials we have experienced together! It is never without tenderness of heart that we say, ‘we have had the same thoughts, affections and hopes. Such an event penetrated us with common joy; such another filled us with grief. Uniting our efforts, we rescued a victim of poverty and misfortune. We mutually shared his tears of gratitude. The hard necessity of circumstances separated us; and our paths so diverged that seas and mountains divided us. But we still remained present to each other, in communion of thought. He had fears for me, and I for him, as we foresaw each other’s dangers. I learned his condition, interpreted his thoughts and feelings, and said, ‘such a fear agitates him; he forms such a project, conceives such a hope.’ Finally, we met again. What charms, what effusion of heart in the union!’ It is a puerile absurdity to be proud of the reputation of one to whom we are united by the ties of blood—a distinction which nature gave us. But we may be justly proud of the rare qualities of our friend. The ties of this relation are not the work of nature or contingency. We prove that, in meriting his esteem, we, at least, resemble him in the qualities of his heart. I immediately form a high opinion of the man whom I hear earnest in the applause of the talents or virtues of his friend. He possesses the qualities which he applauds; since he has need to affirm their existence in the person he loves. This noble and pure sentiment has had its peaceable heroes. What names, what examples could I not cite, in ancient and in modern times! What splendid and affecting proofs of identity of fortune, joys and sorrows, and even danger and death! I knew two friends, of whom every one spoke with respect. One of them was asked the
- 38. extent of his fortune? ‘Mine is small,’ he replied, ‘but my friend is rich.’ The other, a few days before he died of a contagious disease, asked, ‘why so many persons were allowed to enter his chamber? No one,’ he added, ‘ought to be admitted but my friend.’ Thus were they one in fortune, in life and in death.[36] I deem, that even moralists have sought to render this peaceable sentiment, this gentle affection, and the only one exempt from storms, too exclusive. I am aware, how much our affections become enfeebled, in proportion as their objects multiply. There is force in the quaint expression of an old author. ‘Love is like a large stream which bears heavy laden boats. Divide it into many channels, and they run aground.’ Still, we may give the honored name of friend to several, without profaning it, if there exist between us mutual sympathy, high esteem and tender interest; if our pleasures and pains are, in some sense, common stock, and we are reciprocally capable of a sincere devotion to each other’s welfare. As much, however, as I revere the real sentiment, I am disgusted by the sickly or exaggerated affectation of it. The sentiment is still more delightful when inspired by a woman. I shall be asked, if it can exist in its purity between persons of the different sexes? I answer in the affirmative, when the impulses of youth no longer agitate the heart. We then experience the whole charm of the sentiment, as the difference of sex, which is never entirely forgotten, imparts to it a vague and touching tenderness and an ideal delight for which language is too poor to furnish terms. Why can love and friendship, the sunshine of existence, decay in the heart? Why are they not eternal? But since it is not so, if we are cruelly deceived in our affections, the surest means of medicating our pain is, instead of cherishing misanthropic distrust, to look round and form the same generous ties anew. Has your friend abandoned you? or, worse, has your wife become unworthy of your love? It is better to be deceived a thousand times than to add, to the grief of wounded affection, the insupportable burden of general distrust, misanthropy and hatred. Let these baneful feelings never usurp the
- 39. place of those sentiments which must constitute human happiness. Pardon to those by whom you have been loved, the sorrows which their abandonment has caused you, in consideration of those days of the past which was embellished by their friendship. But these treasons and perfidies are only frequent in the intercourse of those who are driven about by the whirlwinds of life; in which so many opposing interests, so many deceitful pleasures confuse and separate men. The simple minded and good, whose days flow pleasantly in retreat, every day value more the price of those ties that unite them. Their happiness is veiled and guarantied by a guardian obscurity. I give place to none of the illusions of inexperience in regard to men.[37] The errors, contradictions and vices with which they are charged, exist. I admit that the greater part of satires are faithful paintings. But there are still to be found, everywhere, persons whose manners are frank, whose heart is good, and whose temper amiable. These persons exist in sufficient numbers to compose this new world of which I have spoken. Writers are disposed to declaim against men. I have never ceased to feel good will towards my kind. I have chosen only to withdraw from the multitude, in order to select my position in the centre of a small society. For me there are no longer stupid or wicked people on the earth. I have examined the essential things of life, tranquillity and independence of mind, health, competence and the affection of some of our kind. I wish now to give my observations something more of detail and diversity. But I wish it still to be borne in mind, that I give only the materials and outlines of an essay, and make no pretensions to fill out a complete treatise. I wish that a temple may be raised to happiness. Hands, more skilful than mine, will rear it. It is sufficient to my purpose to indicate those delightful sites, in the midst of which it may be erected.
- 41. L E T T E R X V I I . T H E P L E A S U R E S O F T H E S E N S E S . Nature has decreed, that each one of our senses should be a source of pleasure. But if we seek our enjoyment, only in physical sensations, the same stern arbiter has enacted, that our capability of pleasure should soon be exhausted, and that, palled and disgusted, we should die without having known true happiness.[38] Exactly in proportion as pleasures are less associated with the mind, their power to give us any permanent satisfaction is diminished. On the contrary, they become vivid and durable, precisely in the degree in which they awaken and call forth moral ideas. They become celestial, when they connect the past with the present, the present with the future, and the whole with heaven. In proportion as we scrutinize the pleasures of the senses, we shall always find their charm increasing in the same degree, as losing, if I may so say, their physical stain, they rise in the scale of purification, and become transformed, in some sense, to the dignity of moral enjoyments. I look at a painting: it represents an old man, a child, a woman giving alms, and a soldier, whose attitude expresses astonishment. I admire the fidelity, the truth and coloring of the picture; and my eye is intensely gratified. But remaining ignorant of the subject, I go away, and the whole shortly vanishes from my memory. I see it again; and am now struck with the inscription at the bottom, ‘Date obolum Belisario.’ I remember an interesting passage of history. A crowd of moral images throng upon my spirit: I soften to tenderness; and I comprehend the affecting lesson, which the artist is giving me. I review the painting, again and again; and thrill at the view of the blind warrior, and of the child holding out his helmet to receive alms.
- 42. When we travel, those points of view in the landscape which long fix our eye, are those which awaken ideas of innocence and peace; affecting the heart with associations connected with the morning of our life; or ideas of that power and immensity, which move and elevate the soul. The paintings of nature, as well as those of men, are thus capable of being embellished by moral associations. In travelling, I perceive a delightful isle embosomed in a peaceful lake. While I contemplate it, with the simple pleasure excited by a charming landscape, I am told that it is inhabited by a happy pair, who were long crossed and separated; but who wore out the persevering opposition of fortune; and are now living there in the innocence and peace of the first tenants of paradise. How different an interest the landscape now assumes! I behold the happy pair, without care or regret, sheltered from jealous observation, enjoying the dream of their happy love, gratefully contemplating the Author of the beautiful nature around them, and elevating their love and their hearts, as a sacrifice to HIM. Sites, which, in themselves, have no peculiar charm, become most beautiful as soon as they awaken touching remembrances. Suppose yourself cast by misfortune on the care of a stranger in a strange land. He attempts to dispel your dejection, and says, ‘these countries are hospitable, and nature here puts forth all her opulence; come, and enjoy it with us.’ The gay landscapes, which spread before you, all assume the appearance of strangers; and offer no attractions. But while your eye traverses the scenery with indifference, you see blue hills melting into the distant horizon. No person remarks them, but yourself. They resemble the mountains of your own country, the scenes upon which your infant view first rested. You turn away to conceal the new emotions, and your eyes are filling with tears. You continue to gaze fondly on those hills, dear to memory. In the midst of a rich landscape, they are all that interests you. You return to review them every day, and demand of them their treasured remembrances and illusions,—the dearest pleasures of your exile.[39]
- 43. All the senses would offer me examples, in illustration of this idea. Deprive the pleasures of physical love of moral associations, which touch the heart, and you take from it all that elevates the enjoyment above that of the lowest animals. Else, why do modesty, innocence, the expression of unstained chastity, and the graces of simplicity possess such enchanting attractions? The truth, that there exists in love a charm stronger than physical impulse, is not unknown even to women of abandoned manners. The most dangerous of all those in this unhappy class, are they, who, not relying on their beauty, feign still to possess, or deeply to regret those virtues, which they have really cast away. There are useful duties upon this subject, which I should find it difficult to present in our language. In proportion as the manners of a people reach the extreme refinement of artifice and corruption, their words become chaste. It is a final and sterile homage rendered to modesty. The last delights which imagination can add to the pleasures of love, are not to be sought in those vile places where libertinism is an art. We must imagine the first wedded days of a young and innocent pair, whose spirits are blended in real affection, in similar tastes, pursuits and hopes, who realize those vague images which they had scarcely allowed before to float across their mind. They who seek in the pleasures of taste only physical sensations, degrade their minds and finish their useless existence in infirmity and brutal degradation. The pleasures of taste should only serve to render the other enjoyments more vivid, the imagination more brilliant, and the pursuits of life more easy and pleasant.—All objects should present themselves under a gay aspect. A happy veil should shroud those pains which have been, or are to be endured. Even the wine cup, more powerful than the waters of Lethe, should not only procure forgetfulness of the past, but embellishment of the future. The pleasures derived from odors are only vivid, when they impart to the mind a fleeting and vague exaltation. If the orientals indulge a passion for respiring perfumes, it is not solely to procure pleasurable
- 44. physical sensations. An embalmed atmosphere exalts the senses, and disposes the mind to pleasant revery, and paints dreams of paradise upon the indolent imagination. Were I disposed to present the details of a system upon this subject, the sense of hearing would offer me a crowd of examples. The brilliant and varied accents of the nightingale are ravishing. But what a difference between hearing the melody from a cage, and listening to the song at the noon of night, when a cool and pure air refreshes the lassitude of the burning day, and we behold objects by the light of the moon, and hear the strains of the solitary bird poured from her free bower! A symphony, the sounds of which only delight the ear, would soon become wearying. If it have no other determinate expression, it ought, at least, to inspire revery, and produce an effect not unlike that of perfumes upon the orientals. Suppose we have been at an opera, got up with all the luxury of art. Emotions of delight and astonishment rapidly succeed each other, and we believe it impossible to experience new sensations of pleasure. In returning home, we chance to hear in the distance, through the stillness of night, a well remembered song of our infancy, that was sung to us by some one dear to our memory. It is at once a music exciting more profound emotion, than all the strains of art which we so recently thought could not be surpassed. The remembrances of infancy and home rush upon the spirit, and efface the pompous spectacle, and the artificial graces of execution.[39a] Observations to the same effect might be multiplied without end. If you desire pleasures, fertile in happy remembrances, if you wish to preserve elevation of mind and freshness of imagination, choose, among the pleasures of the senses, only those which associate with moral ideas. Feeble, when separated from the alliance of those ideas, they become fatal when they exclude them. To dare to taste them, is to sacrifice happiness to pleasures which are alike ephemeral and degrading. It is to resemble him, who should strip the tree of its flowers, to enjoy their beauty. He loses the fruits