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ON

ORGANIC POLARITY.

SHEWING

A CONNECTION TO EXIST BETWEEN

ORGANIC FORCES

AND

ORDINARY POLAR FORCES.

yf

By H? F BAXTER, Ese.

MEMBER OF THE ROYAL COLLEGE OF SURGEONS, ENGLAND.

LONDON,
JOHN CHURCHILL, NEW BURLINGTON STREET.
MDCCCLX.

KS
PREFACE.

Tue following Essay contains the results of an
investigation which has occupied my attention for
some time, subject, however, to the interruptions
necessarily connected with professional life. They
have for the most part already appeared in Papers
published on various occasions, viz. in the Philo-
sophical Transactions, and the Proceedings of the
Royal Society of London, the Philosophical Magazine,
the Edinburgh New Philosophical Journal, and the
Transactions of the Cambridge Philosophical Society,
but they are now collected and published in a more
connected form, with a hope that they may lead to
future inquiries.

Objections might be raised to the title of this
Essay, Organie Polarity. The results of these in-
vestigations lead me to consider it as the most appro-
priate. It was not selected as the original title to
my Papers, but the conclusions that I have arrived
at induce me to believe that we have to deal with
polar forces, since there can be no doubt that some,
if not all, of the organic actions which take place in
the living body are accompanied with the mani-
festation of electrical action. I might have entitled
iv PREFACE.

it, Researches in Animal Electricity, or Electro-
Physiological or Biological Researches, but the ab-
surdities associated with the facts comprised under
these titles, such as Animal Magnetism, Mesmerism,
&c. would only tend to continue, instead of remove,
the confused notions connected with the subject,
and also the strong prejudices that are entertained
in reference to it.

With regard to the conclusions I have arrived
at, I am not aware that any serious attempt has been
made by experimental evidence to prove them erro-
neous. The objections that have been raised partake
unfortunately too much of a personal character.
Opposition has been started, in consequence of
having in my first Paper, which was communicated
and published in the Transactions of the Royal
Society, entitled it an attempt to apply some of
the discoveries of Farapay to Physiology; and as some
vagueness seemed at the time to be expressed in this
title, and to avoid any misconception, I endeavoured
in a note to render my meaning more explicit, and
to point out the necessity of being acquainted with
Farapay’s views in regard to current force. Since
then, I have been told that ‘ Farapay knows nothing
of the subject,’ and that ‘ Grove’s views are the most
correct,’ with other observations which I refrain from
relating. It was not my intention, nor had I the
least idea at the time, that it would be made and
become the subject of a personal affair; but I felt
and considered myself bound to state to whom I had

Bea di

 
PREFACE. v

been indebted for any success that might attend my
labours; for any one at all conversant with experi-
mental researches will readily acknowledge, that
to make any advance -in the special subject of his
inquiry, it becomes absolutely necessary for him to
obtain some clear ideas in regard to the subject of
his investigations; and I do not think it can be
supposed for a moment, that an individual could,
without some preliminary knowledge of the subject
under consideration, expect to arrive at any definite
and trustworthy results. In short, to make any
progress in’ any one particular branch of science
would almost appear to depend necessarily upon a
previous advanced state of another corresponding
branch. I do not suppose any one will deny this;
at any rate, it is a conviction that experience has
forced upon my mind. I was not so well acquainted
with Mr. Grovz’s views when my Paper was pub-
lished as at the present time; and, without wishing
to derogate from his well-earned reputation as an
experimentalist, I have no hesitation in saying, that
subsequent knowledge of the subject has only con-
vinced me more than ever of the justness of my first
opinion ; and I still believe that Farapay’s views will
be found to be by far the most philosophic.

I may perhaps have omitted to notice the results
obtained by other investigators, which ought to
have been alluded to; if so, I have to apologize for
the omission; it has been unintentional. I have
not attempted to write a Treatise on the subject.
vi PREFACE.

My chief object has been to bring prominently
forward those facts which appear to me to be
supported by experimental evidence, and of paramount
importance; the application of these facts must be a
subject for future consideration.

I may observe, in conclusion, that whatever suc-
cess may have attended my labours, I cannot lay claim
to any originality; for I shall have the pleasure of
shewing, that our predecessors, with all our boasted
advantages of superior means of investigation, enter-
tained very correct notions upon the subject. They
pursued and exhausted the subject as far as they
could, and then threw out conjectures for others
to verify.

CAMBRIDGE,
September, 1860.
CONTENTS.

CHAP. I.

Historical Sketch: Walsh; Galvani; Volta; Humboldt; Vassali
Eandi; Wollaston; Nobili; Matteucci; Du Bois Reymond. pd

CHAP. II.

Of the Force evolved during Chemical Action: First, in the
Voltaic Circle; Secondly, in the reaction of different Solutions
upon each other.—Of Differential Currents.—Of Combined
Currents.—The Force, a Polar Force, and its definition. 12

CHAP. IIt.
Galvanometer. Precautions to be observed. - e 21

CHAP. Iv.

On the Manifestation of Current Force during the Organic
Process of Secretion in the living or recently-killed Animal:
in the Stomach and Intestines; the Liver; the Kidney; the
Mammary Gland; the Lungs. . ‘i 2 ! 5 25

Sect. I. During the formation of the Secretions in the
Mucous Membrane of the Alimentary Canal, viz.
the Stomach and Intestines. ‘ ‘ z 28

Secr. II. During Biliary Secretion. . 3 ‘: 87

Secr. ITI. During Urinary Secretion. : . 41

Sect. IV. During Mammary Secretion. . . 44

Srcr. V. During Respiration. 3 e c 46
CHAP. V.

On the Manifestation of Current Force Gee Lacteal Ab-

sorption. . ‘ z a ‘ . J 56
CHAP. VI.

On the Manifestation of Current Force during Nutrition. In

the Muscular Tissue. In the Nervous Tissue. 5 61

Sscr. I. During Nutrition in the Muscular Tissue. 61
Srct. Il. During Nutrition in the Nervous Tissue. 68
viii CONTENTS.

CHAP. VII.
On the Electric Condition of the Blood. . ‘ : 7
CHAP. VIII.

On the Electric Condition of the Muscular and Nervous Tissues.
Muscular Current. Nerve Current. Polarized Condition of
the Muscular Tissue and of the Nerve Tissue. § 74

CHAP. IX.

On the Polarized Condition of the Muscular and of the Nervous

Tissue in the living or recently-killed Animal. Muscular

Force and Nerve Force, Polar Forces. . . : 90
CHAP. X.
On the Manifestation of Electric Force, of Chemical Force, and
of Heat, during Muscular Contraction. . . 108
Secr.I. Manifestation of Electric Force during Muscular
Contraction. ‘ 108
Sect. II. Manifestation of Ghertaal eon: during
Muscular Contraction. . : 5 5 . 127
Szcr. III. Manifestation of Heat during Muscular
Contraction. : - . . F . 1380
CHAP. XT.

On Nerve Force. Not Current Force, shewn by the Galvanometer,
the ee Frog, and the Magnetic Needle. A Polar

Force. : ‘i . . 4 i . . 133
Szcr. I. The Galvanometer. . 3 “ . 137
Szcr. II. The Galvanoscopic Frog. . : ‘ 140
Sect. III. The Magnetic Needle. . 5 ‘ 143

CHAP. XII.
On the Manifestation of Current Electricity in Plants during

Vegetation. . ‘ . 3 : . . . 159
Szcr.I. In the Leaves of Plants, . “ a 162
Szor. IT. In the Roots of Plants. . ‘ cD 169
Sscr. III. In the Petals. . é . 7 174
Srct. IV. In Fruits and Tubers. . é 175

CHAP. XIII,

Conclusion. . ‘ : . ‘ i 178
ORGANIC POLARITY.

CHAP. I.

HISTORICAL SKETCH: WALSH; GALVANI; VOLTA; HUM-
BOLDT; VASSALI EANDI; WOLLASTON; NOBILI; MAT~
TEUCCI; DU BOIS REYMOND.

Ir is not my intention to enter upon a critical
review of the various opinions that have been enter-
tained in regard to the developement of electrical
action in living animals, nor of the facts bearing
upon the question of the influence of electricity
upon organic actions; but I will endeavour to give
a slight historical sketch of those fundamental facts
which may be adduced as evidence of the mani-
festation of electrical action in the animal body.
It will, however, frequently happen, that some
difficulty may be experienced in determining this
point, as may be seen in the controversy that
occurred at the time of GaLvanr and Vora’.

a The followimg works may be referred to.
Traité de? Electricité et du Magnétism, 7 vols. par M. BEcQUEREL.
Paris.
Traité des Phénoménes Electro-Physiologiques des Animauz,.
par M. Marteucct, Paris, 1844; and to his Papers published.
B
2 HISTORICAL SKETCH. CHAP. I.

That certain fish have the power of giving 4
shock to the human body has been long known,
and even employed by the natives of the country
in which they are found for remedial purposes; just
as the physicians in the middle of the eighteenth
century were in the habit of employing the shocks
from the electrical machine in the cure of disease.
The shock from the fish and that from the Leyden
jar led philosophers to entertain the belief, that
they were identical as to their nature, and due to
the same power, viz. Electricity; whence arose the
term, Animal Electricity.

In 1773, WatsH>, in his experiments on the
Torpedo, proved to a certain extent this identity:
he obtained the spark, but could not get any evidence
of attraction and repulsion. He compared the action

since that period in the Philosophical Transactions of the
Royal Society of London, and in the various continental
scientific Journals.

Du Bors Reymonn’s large work in German, an abstract of
which has appeared in English, edited by Dr. Bence Jones,
entitled, Animal Electricity, London, Churchill, 1852; and to a
Review of the same by Prof. Tyndall, in the British and Foreign
Medical Review, Jan. 1854, p. 141.

Rapport sur les Mémoires rélatifs aux Phénoménes Electro-
Physiologiques présentés a UAcadémie, par M. E. pu Bors
Reymond. Comptes Rendus, vol. xxxi. p. 28.

Dr 1a Rivz’s Treatise on Electricity, translated by Walker,
3 vols. Longman.

A Paper published in the Edinburgh New Philosophical
Journal, Oct. 1855, entitled, 4 brief Review of the Present State
of Organic Electricity. By Prof. Goopsir, F.R.S.L. and E.

b Philosophical Transactions, 1773.
CHAP. I. GALVANI. 3

of the electric organ to that of a Leyden jar.
“The electricity of the Torpedo,” he says, “is
entirely due to the batteries; their upper and under
surfaces are capable, from a state of electric equi-
librium, of being instantly thrown, by a mere energy,
into a plus and minus state, like that of a charged
phial, and the current results from a conducting
medium between their opposite surfaces being sup-
plied naturally or artificially.”

Since that period, several philosophers have under-
taken the examination of the electric power of the
fish, and the identity between these two powers,
that of the fish and of ordinary electricity, has been
satisfactorily proved; attraction and repulsion have
been obtained, the galvanometer has been affected,
chemical decomposition produced, and magnets made ;
but even at this early period, some of the most
important facts connected with animal electricity
were well known; and, without intending to de-
preciate the labours of Gatvan1, men’s minds were
well prepared at his time to seize upon any new fact
that might arise.

In 1791, Gatvant published his celebrated Com-
mentary, entitled, De Viribus Electricitatis in motu
musculart Commentarius; but prior to that he was
evidently well acquainted with the circumstance,
that the discharge from an electrical machine would
produce convulsions in a frog. This discovery has
been attributed to chance; to the circumstance, that
some frogs had been prepared for making broth for

*
4 HISTORICAL SKETCH. CHAP. I.

his wife, and were accidentally lying within the in-
fluence of an electrical machine when in action.
Upon reading over the various accounts it appears
to me, that the accidental fact observed at the time,
and one of the most importance, was the following:
one of his assistants happened to touch the crural
nerves of a frog with the point of a scalpel, when
contractions of the muscles of the limbs occurred,
(a fact well known to physiologists of the present
day.) Ga vani intuitively saw that effects were now
obtained by the mere point of the scalpel, similar to
those that had been previously observed when a
spark or a shock from the conductor of an electrical
machine traversed the nerve of the animal. Here
was a new cause producing muscular contractions, a
new source of power. It was no longer necessary to
have the electrical machine, the mere point of the
scalpel was sufficient.

From our present position we may readily con-
ceive the train of ideas and questions that passed
through Gaxvani’s mind. A new fact was to be
accounted for. Why, he might have asked, should
not the cause exist in the animal body, for we have
the developement of the power in the fish, as indi-
cated by the shock, which is similar to that of a
charged Leyden jar, and this shock depends upon
the will of the animal.

The experiments of Gatvanr were repeated in
various ways, and by other experimentalists, and
amongst them Vorra stands preeminent. The facts

a
CHAP. I. VOLTA. 5

were not denied; the dispute arose as to the ex
planation of them, and the controversy that succeeded
is one of extreme interest. Amongst other import-
ant results, the following fundamental facts were
established. One by Gatvan1, who shewed that
when a circuit is formed by means of any conducting
substance, whether metals or not, between the nerve
and the muscle, muscular contractions are produced
in the muscles supplied by that nerve, and that the
contractions. may be produced even when the free
end of the nerve alone. touches the external surface of
the muscle. The other by Vouta, who shewed that
the contractions were the greatest when two hete-
rogeneous metals were employed to complete the
circuit, and that contractions would also be pro-
duced when a portion of the nerve alone was
included within the circuit. Gatvant explained the
effects, by supposing that the muscles acted as
reservoirs of electricity, similar to a charged Leyden
jar, electricity being formed by the brain; (over-
looking the possibility, pardonable at his time, that
other parts as well as the brain might produce
electricity ;) and that the inner and outer surfaces of
the muscles being in opposite electric states, when
the circuit was completed the contraction of the
muscle ensued in consequence of the reunion of
the electricity of the two surfaces. Voxra, on the
other hand, considered that the effect was due to
the electricity which was developed by the mere
contact of the heterogeneous metals, or other sub-
6 HISTORICAL SKETCH. CHAP. I.

stances by means of which the circuit was completed.
Both Gazvanz and Vouta considered, however, that
the effect, the contraction of the muscle, was evidence
of the manifestation of electrical excitement; in
fact, the limb was then, as it is employed at the
present day, an indicator of electrical action. Both
were wrong in their exclusive notions respecting the
origin of the power; Gatvani in denying or over-
looking the circumstance, that the power might
partly arise from the contact of the heterogeneous
substances forming the circuit; Voxra, on the other
hand, in denying the origin of the power in the
animal body.

Homsotpt’, from his numerous experiments, came
to the conclusion, that the effects could not be en-
tirely referred to the mere, contact of the metals
as suggested by Voxra, but that they were partly due
to some cause originating in the animal.

I shall now refer to a communication published
at this period, in which will be found a concise view
of the then state of knowledge upon the subject.
It is of some value, inasmuch as it is a letter written
by Vassari Eannr, at that time one of the celebrated
professors at Turin, to M. DeLamerurtie, then Secre-
tary to the Royal Academy of Paris, who requested
his opinion “upon galvanism, and the origin of
animal electricity*.” The position these two

* Experiences sur le Galvanisme, Paris, 1799.
4 Lettre de Vassazr Eanpi, A J. C. DEtameraerm. Sur le
CHAP. I. VASSALI EANDI. 7

individuals held might be adduced as giving some
weight to their authority; and in it will also be found
the details of some experiments, anticipating those
of the present day. “Si on compare,” writes Vassazr
Hanopr, ‘le corps animal a la bouteilie de Leyde
lorsqu’on approche l’are conducteur 4 la boule qui
communique avec l'intérieur de la bouteille tandis
que l’autre extrémité de cet arc en touche la partie
extérieure, on voit les corps Jégers s’élancer de la
boule a l’arc; le méme phénoméne devrait avoir lieu
dans la bouteille de Leyde animal, si je puis me
servir de cette expression; cependant, quoique le
D. Valli, le professeur andi et plusieurs autres ayent
écrit quils ont observé des mouvements électriques
dans l’expérience de Galvani,.comme il s’agit d’une
expérience qui exige la plus grande delicatesse, ce que
la moindre haleine agissant sur les corpuscules
légers, peut tromper l’observateur, je vous dirai
franchement que j’ai répété plusieurs fois cette ex-
périence en changeant l’appareil en faisant usage
de feuilles d’or, et d’autres corps trés-legers, et je
n’ai jamais pu m’assurer qu'il en résultat des mouve-
ments électriques.” (We here see, that the evidence
requisite at that time to confirm Gatvant's conjecture
did not exist, viz. the attraction and repulsion of light
bodies; the fact being, that the force does not appear
to be of sufficient intensity to produce these effects.
The only evidence that could be adduced was the

galvanisme et sur Vorigine de Vélectricité animale. Journal de
Physique, t. xlviii. p. 836, 1799. Germinal, an. vii.
8 HISTORICAL SKETCH. cHAP, I.

effect upon the galvanoscopic limb, viz. when the
nerve was laid over on to the surface of the muscles
of the same limb, and which were supplied by the
same nerve, and thus producing contractions; but
this could not be deemed satisfactory, without begging
the question; the existence of the power in the fish
was of some importance, as confirming the con-
jecture.) Vassatt Eanpt goes on to state; “ Si javais
une opinion a émettre, je serais porté a croire que les
contractions musculaires sont produites par le mouve-
ment de Vélectricité animale dirigée par les con-
ducteurs de V’électricité naturelle; car, sans alléguer
en preuve de cette opinion les faits innombrables
publiées par les D. Gardini, Bertholon, Cotugno,
Galvani, Aldini, Valli, Eandi, Giulio, Rossi, Volta,
&c. j’observerai seulement que dans la nature, chaque
corps changeant son état chimique, change aussi sa
capacité propre a contenir le fluide électrique, et
méme bien souvent il change de nature par rapport
a Vélectricite comme on le voit dans les oxides
métalliques. Or puisqu’il n’y a aucun doute que
lair dans la respiration, et les alimens, dans la
digestion, ne changent d’état chimique, ils changeront
done aussi de capacité pour le fluide électrique.
Réad a démontré que lair dans la respiration, perd
son électricité naturelle; j’ai prouvé ailleurs que les
urines donnent une électricité négative et j’ai fait
voir plusieurs fois aux D. Gerri, Garetti, et aux éléves
de médecine et de chirurgie, que le sang tiré des
veines, donne dans mon appareil électrométrique

ee Mament Al one
CHAP. I. VASSALI EANDI. 9

(décrit dans le vol. v. de Académie des Sciences de
Turin, Dec. 19, 1790,) une électricité positive; done
Vélectricité naturelle de lair et des aliments reste
dans certaines parties du corps en abondance, tandis
que dans le méme corps il y a d’autres parties qui,
n’en ont pas la quantité proportionnée a leur
capacitée.” ‘

We shall find that the vast mass of facts accu-
mulated at this period by Ganvani, Vora, and other
experimentalists, required for their full developement
a knowledge of a different order of phenomena
than those of ordinary electricity, or such as are
associated with static electricity. The developement
of the phenomena connected with current electricity
and that from chemical action, together with the
means of studying this form of electrical action,
namely, the galvanometer, were now required,
affording sufficient evidence for shewing, that the
different departments of science are so intimately
and mutually connected, that any advance in one
is necessarily dependent upon a corresponding
advance in another.

Shortly after Gatvani’s death, Vorra introduced
the pile, the voltaic battery; and as he could now
obtain the effects without the intervention of organ-
ised substances, he was further confirmed in his
opinion as to the origin of the power being inde-
pendent of the animal body; in short, he denied
the existence of Animal Electricity. Men’s minds
were now completely withdrawn from the subject of
10 HISTORICAL SKETCH. cHAP. I.

Animal Electricity ; and the next question that arose
was that of the origin of the power in the Voltaic
circle, whether by a contact or by chemical action.
A fresh subject of controversy was now introduced,
and one which has continued up to the present
day. .

In 1806, Davy astonished the scientific world by
his well-known discovery of the decomposition of the
alkalies by means of the Voltaic battery, and esta-
blished the important fact, that acids were evolved
at one pole and alkalies at the other pole of the
battery, from whence arose the phrase polar decom-
position. WotuasTon immediately seized upon the
idea, that animal secretions were effected by the
agency of a similar electric power, and published an
important Paper containing his views. As I have
quoted this Paper in the chapter on the Secretions,
I shall only now allude to it. Dr. T. Youne4 also:
entertained views somewhat similar to those of
Wottaston, but being unsupported by direct ex-
perimental evidence, they need not be detailed.

OrrsteD’s celebrated discovery in 1820, that a
magnetic needle was influenced by an electric
current, led to the introduction of the galvanometer ;
and in 1827, Noprui, in his endeavours to ascertain
whether this new instrument could equal the delicacy
of the galvanoscopic frog in its indications of elec-
trical action, established the important fact, that
a current of electricity existed in the limbs of the

4 Medical Literature, p. 111.
CHAP. I. NOBILI, MATTEUCCI, DU BOIS REYMOND. 11

frog, being directed from the feet to the sciatic
plexus, or towards the head of the animal, and this
he called ‘the proper current of the frog.’ SrEBecx had
shortly before ascertained the fundamental facts
connected with thermo-electricity; and Nott, strange
to say, was led to believe, that the results he had
obtained with the limb of the frog were due to the
difference of temperature between the nerves and
the muscles. An interesting example, indicating
how prone the mind is to refer any unexplained or
residual phenomenon to a newly-discovered class of
facts.

Since the introduction of the galvanometer, several
observers have attempted to ascertain the existence
of electric currents in the living animal. Amongst
them Marrzvccr stands preeminent, as having esta-
blished several important facts connected with the
developement of electrical action in the animal body ;
and to Du Bois Rrymonp also science is indebted
for the elucidation of several important points
connected with our present subject. As I shall
have occasion hereafter to allude to the results
obtained by these and other philosophers, they need
not now detain us.
CHAP. II.

OF THE FORCE EVOLVED DURING CHEMICAL ACTION :
FIRST, IN THE VOLTAIC CIRCLE; SECONDLY, IN THE
REACTION OF DIFFERENT SOLUTIONS UPON EACH
OTHER.—OF DIFFERENTIAL CURRENTS.—OF COMBINED
CURRENTS.—THE FORCE, A POLAR FORCE, AND ITS
DEFINITION.

As the facts connected with the developement of
electrical action in the living body are so intimately
related to those which occur during ordinary
chemical action, I shall in the present chapter
confine my observations chiefly to the developement
of electricity under these circumstances, and speak,
first, of the electric power, or force, as it exists in
the voltaic circle; and, secondly, of the power as it
exists during ordinary chemical action—during the
reaction of different chemical solutions upon each
other. ;

First: Of the force as tt exists in the voltaic circle.
The form which electricity assumes in the voltaic
circle, and termed current force, is an indisputable
fact, granted both by the contact as well as by the
chemical theorists. As the mass of evidence in
favour of the chemical origin of the power in the
circle preponderates over that of the contact theory,
CHAP. IT. VOLTAIO CIRCLE. 13

I shall confine my remarks to the former, and state
what the chemical theory is*

‘The chemical theory,’ says Farapay, ‘ assumes,
that at the place of action the particles which are in
contact act chemically upon each other, and are able
under the circumstances to throw more or less of
the acting force into dynamic force; that in the
most favourable circumstances the whole is con-
verted into dynamic force; that then the amount of
current force produced is an exact equivalent of the
original chemical force employed; and that in no
case (in the voltaic pile) can any electric current be
produced, without the active exertion and con-
sumption of an equal amount of chemical force
ending in a given amount of chemical change.’

Let us now take a simple voltaic circle, and study
the changes that occur in it. I shall assume my
readers to be acquainted with the origin of the
terms, ‘ electrode,’ ‘ anode,’ and ‘ cathode.’ If we take
a vessel containing dilute sulphuric acid, and dip
two rods, one of zinc and the other of platinum,
into it, so long as they remain separate no action
occurs on the platinum, but gas is evolved on the
zine, where chemical action is taking place. Let the
two rods be brought into communication by means
of a conducting substance, such as a metallic wire,

a I cannot do better than refer my readers to Faraday’s
Paper, On the source of the power in the Voltaic pile. Expe-
rimental Researches, vol. ii. p. 18.

b Tbid. vol. i. p. 195.
14 VOLTAIC CIRCLE. CHAP. II.

and the gas is now evolved on the surface of the
platinum rod, but the chemical action still continues
upon the zinc; in addition to this, we have a
current of electricity, as it is called, in the wire, as
may be shewn by suspending a magnetic needle
parallel to the wire, when the needle will place
itself at right angles to it. The explanation of these
actions is the following: the oxygen of the water
(the electrolyte) combines chemically with the zine,
and the hydrogen, the other element of the electro-
lyte, is evolved upon the surface of the: platinum ;
during these actions electricity is evolved, and the
circuit being completed, it is thrown into dynamic
force, current force. The water is the decomposing
electrolyte; its anion, the oxygen, combines at the
anode with the zinc; whilst the cation, the hydrogen,
is evolved on the surface of the cathode, the platinum.
The sulphuric acid, by dissolving the oxide of zinc
as it is formed, removes it from the surface of the
zinc, and thus assists in continuing the chemical
action®.

Now the direction of the current is invariably
associated with the direction in which the active
chemical forces oblige the anions and cations to
move in the circuit. In the circle we have been
speaking of, the action was at the anode, at the zinc

¢ A different view may be taken in regard to this explanation
of the action of the sulphuric acid. See Daniell and Miller,
on the nature of Compound Electrolytes. Philosophical Trans-
actions, 1839, p. 97.
CHAP. II. VOLTAIC CIRCLE. 15

surface, and the direction of the current was in the
direction the cation hydrogen may be supposed to
move, viz. from the zine across the fluid to the
platinum, the platinum being the positive electrode.
I may just observe, that in the majority of instances
the exciting action is at the anode, and the metal
acted upon is considered as positive to the other
metal; but when we speak of the positive extremity
of the current, this is generally in contact with the
metal not acted upon. It is as well to bear this
in mind, otherwise it will lead to considerable
confusion of ideas, when speaking of the positive
electrode and positive metal.

In the following arrangement, if we take peroxide
of manganese, sulphuret of potassium in solution
as the electrolyte, and platinum, and form them
into a circuit, the platinum will be negative to the
peroxide of manganese; the current will be in the
reverse direction to that observed in the former
arrangement. Now whether we suppose the cation
potassium to abstract the anion oxygen from the
peroxide or the latter, the cation potassium from the
sulphur, still the current passes in the direction
that the cation the potassium may be supposed to
move in the circle, and in this case the peroxide
will not only be the positive electrode, but will also
form the so-called positive metal of the circuit.

In the following circuit, zinc, muriatie acid, and
peroxide of lead, the acting points, are at both
extremities, at the anode and cathode. In this in-
16 CHEMICAL ACTION. CHAP. II.

stance the two acting points assist each, and so
produce a powerful current; the platinum will form
the positive electrode. But here it may be asked,
which forms the positive metal ?

In all these instances we must not overlook the
circumstance of the decomposition of the electrolyte ;
we have a combination and a decomposition occurring
at the same time; which of the two may be con-
sidered as the most important act in the deve-
lopement of the force may perhaps be a question
rather difficult to decide. I shall now proceed to
speak,

Secondly, of the developement of current force during
ordinary chemical action, during the reactions of dif-
Serent chemical solutions upon each other. If we take
a solution of nitric acid and of potassa, place them
on either side of a diaphragm of bladder in a divided
cell, and into each cell place a platinum electrode
and complete the circuit, the electrode in contact
with the acid is positive to the other in the alkali.
In the former instances in the voltaic circle, the
electrode in contact with the alkali, the cation was
positive to the other. With the solutions the current
may be supposed to arise from the combination of the
acid with the alkali; in the voltaic circle to arise
from the decomposition of the compound from the
separation of the alkali from the acid.

According to BroquEREL, nitric acid was found to
be positive with the hydrocholie, acetic, nitrous acids,
alkaline solutions, solutions of the nitrates, sulphates,
CHAP. It. DIFFERENTIAL CURRENTS. 17

muriates, &c. It was negative with sulphuric and
phosphoric acids.

Phosphoric acid was positive with muriatic, sul-
phuric, nitric acids; the dlkaline and saline
solutions.

Water in combining with an acid acts as an
alkali; with alkalies as an acid.

With neutral solutions, the most saturated acted
as an acid to the less saturated. BxrcquEREL con-
siders, that in the reaction of one solution upon
another, that which performs the part of an acid
takes positive, that of an alkali negative electricity.
The effect, it may be observed, that is produced
under these circumstances upon the galvanometer
is nothing like so great as that which occurs with
the voltaic circle, where metals are employed.

Before quitting the subject of the developement of
electricity during chemical action, I shall take the
opportunity of speaking of what are called differential
currents and combined currents. If we take a vessel
or glass cell and divide it into three compartments
by a membrane, so as to form three distinct cells,
and into the extreme compartments pour a solution
of potash, and into the centre one nitric acid, then
place the platinum electrodes of a galvanometer
into the potash cells, no effect will occur upon the
needle, provided the arrangement be perfect; but
if one of the electrodes be placed in the acid, and
the other in the alkali, we then have the ordinary
result. In the former instance the currents pro-

c
18 COMBINED CURRENTS. CHAP. II.

duced, passing in contrary directions and being
equal to each other, counteracted each other’s effects,
and consequently there was no action upon the
needle.

Let the cells be filled thus, acid | alkali | acid |
alkali, and place the electrodes in the extreme cells ;
we have here three acting points in the circuit:
at one point the current is in one direction,
and in two others in a contrary direction; and the
action upon the needle in this instance will shew
the differential result.

The same observations may be made in regard to
a voltaic battery, by altering the arrangements of
the metals, so as to have a combined action in one
case and an interfering action in the other.

I have entered somewhat fully into the develope-
ment of electric action during chemical action, in
consequence of its immediate bearing upon the
question of the developement of electric force during
organic action; and I ought now perhaps to allude
to thermo-electric action, and to the facts connected
with the so-called catalytic action or the combining
power of platinum; but to enter fully into these
questions would occupy too much space, and I must
therefore refer my readers to the published treatises
on Electricity for further information upon these
subjects.

Let us now call to mind the peculiar characters,
without alluding to the origin of the power, whether
from heat, chemical action, friction, &c. which are asso-
CHAP, IT. POLAR FORCE. 19

ciated with electric foree when manifested in its
static, or in its dynamic condition, the former as it is
manifested in a charged Leyden jar, the latter as it
exists in a wire or any conducting medium, when it
assumes the so-called current form. In both in-
stances, in the static and the dynamic condition, we
have the characters of polarity clearly manifested ;
a ‘ duality, an ‘ antithetical action, a ‘ contrast of
properties in a contrast of positions ;’ and it is some-
what surprising to find Mr. Groves, in 1855, at page
152 of his Essay, stating, that “it is difficult to
convey by words a definite idea of the dual or
antithetic character of force involved in the term
polarity,” after the clear definition of it given by
Farapay, as far back as 1833, when he speaks of it
“as an aris of power having contrary forces exactly
equal in amount in contrary directions*.”. In WHEWELL’s
Philosophy of the Inductive Sciences, published in
1840, will be found a very interesting chapter, (Book
V. on the Idea of Polarity,) in which extremely
valuable observations are made in reference to the
same point. However important Mr. Grove’s views,
as published in his Essay, may be considered, and
that they possess some value cannot be denied, I
still believe that the views advanced by Farapay,
and worked out in his admirable Memoirs, are by
far the most philosophic. There is a unity of
thought, a firmness of opinion, and a consistency
about them which bear the stamp of truth. And

4 Experimental Researches, vol. i. p. 148.
20 POLAR FORCE, CHAP. II.

I cannot refrain from observing, that if the views I
have entertained in regard to Farapay’s researches
are so erroneous and inconsistent when compared
with Mr. Grove’s, I really think that some attempt
might and ought by this time to have been made to
prove them as such.
CHAP. III.

GALVANOMETER. PRECAUTIONS TO BE OBSERVED.

Ir will not be necessary for me to enter into the
subject of the construction of the galvanometer, or of
the principles of its action; but merely to observe, that
for the purpose of electro-chemical research, a gal-
vanometer consisting of several coils of thin wire
will be found to be the most appropriate; whilst for
the study of thermo-electric and of magneto-electric
researches, a galvanometer consisting of a few coils
of thick wire or of a plate of copper will be found to
be the best. For our present purpose, the former
with seyeral coils will be found the most applicable ;
‘at the same time we must not overlook the import-
ance of occasionally using the latter.

The mode usually adopted, and found mos
convenient to pursue in these experiments, was as
follows. The galvanometer was placed and well
secured on a firm table or stand, free from any
vibrations of the room, and with a good light falling
upon it, at the same time not exposed to the direct
rays of the sun, so as to avoid the production of
air-currents within the shade of the instrument.
Two thick copper wires, about six inches in length,
were bent at right angles, so that one extremity
should be attached to the instrument by means of
22 GALVANOMETER. CHAP, III.

the binding screws, whilst the other extremities were
dipped into two mercurial cups; by these means the
galvanometer would remain fixed, and it was at these
mercurial cups that the contacts were made and
broken. The electrodes, by means of which the
circuits were formed and completed in the subject
during an experiment, consisted of thick platinum
wires about nine inches in length.

There are several circumstances of paramount
importance to be attended to during an experiment.

First. The arrangement of the galvanometer
should be perfect, and in a good working condition ;
that is to say, the contacts between the different
parts should be complete, and no effects should occur
upon the needle when a circuit is formed between
the mercurial cups: at the same time, the instrument
should indicate any slight action from some well-
known cause, and if delicate, the mere squeezing of
the extremities of the platinum electrodes between
the fingers would be quite sufficient to produce an
effect upon the needle.

Secondly. Avoid having any steel about the person,
such as pen-knives, metallic buttons, or covered
steel buttons in the sleeve of the coat, and when
scalpels are used, the experiment should be com-
menced on a moveable piece of board away from the
galvanometer, and then brought to it. As far as
possible, the galvanometer should be out of the
influence of iron bars, such as those connected with
shutters and fire-irons.
CHAP. III. PRECAUTIONS. 23

Thirdly. Cleanliness is of the utmost importance.
Many experiments have ended in fallacious results
from the mere want of attention to this circumstance.
The platinum electrodes should be perfectly clean,
especially the extremities; they should be well rubbed
with a dry clean cloth, after and previous to the
formation of each circuit during the experiment,
and occasionally exposed to the heat of a clear fire.
The secondary current, due to the polarized state of
the platinum electrodes, must not be forgotten; to
remedy this, the ends of the electrodes should be
dipped into water, and their free extremities brought
into contact so as to form a circuit, and then
cleaned. No acids or alkalies should be employed,
or allowed to come into contact with the hands, or
fingers, or the towels, unless for some purpose in
the experiments: the hands and fingers should be
perfectly clean, and no dirty towels used.

There is one observation to be made in reference
to the employment of the galvanometer. It may be
supposed that a great difficulty is experienced in
obtaining any result with this instrument, and that
it is absolutely necessary to employ a delicate instru-
ment for this purpose; nothing is more fallacious.
There is no difficulty in getting an effect upon the
needle in these experiments, but the contrary; the
difficulty is not to get an effect. In saying this,
however, it is not to be supposed that no satisfactory
results are to be obtained; I only wish to observe,
that it is not the mere motion of the needle and its
24 PRECAUTIONS. CHAP. II.

greatest amount that are to be observed as indicating
the most satisfactory results, but the constant,
steady, and definite motion of the needle; and with
respect to the amount of its deflection, a slight rather
than one of great extent is that upon which the most
trustworthy and satisfactory results are to be placed.
Practice alone, however, can only and would soon
give that knowledge which cannot be obtained by
mere description, and it is by practice alone that any
experiment can be safely undertaken and depended
upon. We must bear this most important fact also
in mind, that it is not the mere circumstance of
getting an effect upon the needle that we are to be
contented with, but we have to account for the effects
when obtained, and to shew to what class of phe-
nomena they may be referred.
CHAP. IV.

ON THE MANIFESTATION OF CURRENT FORCE DURING THE
ORGANIC PROCESS OF SECRETION IN THE LIVING OR
RECENTLY-KILLED ANIMAL; IN THE stomach AND
INTESTINES ; THE LIVER; THE KIDNEY; THE MAMMARY
GLAND; THE LUNGS.

After Davy’s celebrated discovery, in 1806, of the
decomposition of the alkaline salts by voltaic elec-
tricity, and when he had established the important
fact that acids were evolved at one pole and alkalies
at the other pole of the battery, (from whence arose
the phrase polay decomposition,) WotLaston imme-
diately seized upon the idea, that the animal se-
cretions were effected by the agency of a power
similar to that of a voltaic circle; and in the Paper@
containing this remarkable conjecture, which was
published in 1809, he also suggested, that ‘the
qualities of each secreted fluid may hereafter instruct
us as to the species of electricity that prevails in
each organ of the body;” that as the stomach and
kidneys secreted an acid, for example, whilst the
liver secreted an alkaline compound, the two former
might indicate a positive electric state or condition,
and the latter a negative state or condition. Prout?
cautiously advanced a somewhat similar opinion, and
says, “‘ Admitting that the decomposition of the salt

a Philosophical Magazine, vol. xxxiii. p. 488.
b On Stomach and Urinary Diseases, 3rd edit. p. xxv.
26 CUBRENT FORCE CHAP. IV.

of the blood, &c. is owing to the immediate agency
of a modification of electricity, we have in the prin-
cipal digestive organs a kind of galvanic apparatus,
of which the mucous membrane of the stomach and
intestinal canal, generally, may be considered as the
acid or positive pole, while the hepatic system may,
on the same view, be considered as the alkaline or
negative pole. He also quotes an experiment of
Marrevccr as, in some degree, confirming his
opinion.

Downe‘, upon applying one of the electrodes of a
galvanometer to the stomach and the other to the
liver, obtained an effect upon the needle, and the
result of this experiment was subsequently confirmed
by Marrevccr?.

The suggestion thus thrown out, that the stomach
and liver formed poles similar to those of a galvanic
pile, having apparently received some confirmation
from experimental evidence, it now became of some
importance to trace out the circuit, the path of the
current; and, if possible, the origin of the power, so
as to complete the whole evidence necessary for the
proof of the truth of the suggestion.

Reasoning upon these facts, and assuming that
the stomach and liver did actually form the two poles
similar to those of a galvanic circle, it was reasonable
to suppose that the electric current would pass from the
stomach to the liver by the blood in the portal vein. To

* BrcquerEL, Traité de [ Electricité, tom. i. p. 827.
4 Thid. tom. iv. p. 800.
CHAP. Iv. DURING SEORETION. 27

ascertain the truth of this supposition, I now inserted
the two platinum extremities of the electrodes of a
galvanometer into the portal vein, and as far apart
as possible, in order to obtain the supposed diverted
current ; but no effect was observed. The electrodes
were then inserted, one into the portal vein, the other
into the hepatic vein, still no effect.

PovrrzetT?e and Mutier‘, it may be observed, had
previously ascertained that no effect occurred when
they inserted one electrode into an artery, and the
other into a vein, of a living animal.

No evidence could be obtained from these experi-
ments indicative of the path of the current; the
galvanic circle was therefore not complete; and
some of the essential conditions were evidently
wanting.

Repeating the experiments of Marrreuccr upon
other animals than rabbits, the effects observed by
Marrevccr were not always obtained; as these re-
sults will again come under consideration, they need
not now detain us.

Pondering over these failures, it soon became
evident that more correct notions in regard to the
origin of the power in the voltaic circle were re-
quisite; the term current also, with its ordinary
associations, (of something flowing in one direction,)
was a source of great embarrassment; and it was

€ Journal de Physiologie, tom. v. p. 5.

f Mutiur’s Physiology, translated by Baty, vol. i. p. 148.
2d edit.
28 CURRENT FORCE CHAP. Iv. §. L

thus found that a deeper insight into a knowledge of
Farapay’s opinions in respect both to the origin of
the power in the voltaic circle, and to that of current
force in particular, viz. aS AN AXIS OF POWER HAVING
CONTRARY FORCES EXACTLY EQUAL IN AMOUNT IN CON-
TRARY DIRECTIONS, was absolutely essential. I have
endeavoured in chap. ii. to give a brief account of
his views on this point; and I may also refer to
Whewell’s Philosophy of the Inductive Sciences,
vol. i. p. 331. first edition, to the chapter ‘On the
Scientific Application of the Idea of Polarity.’

Dismissing the notion that the stomach and liver
are related to each other in the same manner as the
poles of a galvanic circle are mutually dependent, and
with a more correct knowledge of the origin of the
power in the galvanic circle derived from Farapay’s
memoirs, the thought arose that it might be during
the formation of the secretions where the changes
were actually going on, that the evidence sought
for could possibly be obtained. How far these
surmises were correct will now be seen.

Sscr. I. On the Manifestation of Current Force during
the formation of the Secretions in the mucous mem-
brance of the alimentary canal, viz. the stomach and
intestines.

The mode of employing the galvanometer and of
conducting the experiments, together with the pre-
cautions necessary to be observed, have been alluded
to in chap. iii.
OHAP.IV. §.1. IN THE STOMACH AND INTESTINES. 29

Although experiments performed upon the living
animal may be considered as affording more satis-
factory results, nevertheless, as the results can be
obtained when sensibility is destroyed, the following
mode may be adopted in preference to the use of
chloroform.

Let a few drops of strong prussic acid be dropped
on the nose, insensibility is thus quickly produced ;
or let the animal be pithed, and upon laying open
the chest or abdomen, the heart will be found to
beat and the circulation to continue. Under these
circumstances, if the platinum electrodes of a galva-
nometer are placed one in contact with the mucous
surface of the small or large intestine, the other in
contact with the blood in a vein from the same part,
a deflection of the needle will be obtained indicating
a current through the instrument, the electrode in
contact with the blood being positive to the other in
contact with the mucous surface. If the same
experiment be repeated with the mucous membrane
of the stomach, the effects may vary. If the stomach
be empty, then the electrode in contact with the
blood of the vein coming from the same part will
also be positive; but if there be any food in the
stomach and should it contain much acid, then the
electrode in contact with its mucous surface will
most probably indicate a positive state. Now these
are the fundamental facts and the results, which are
readily obtained with proper precautions, may be thus
summed up: when the electrodes of a galvanometer
30 CURRENT FORCE CHAP. IY. §.1-

are brought into contact one with the mucous surface of
the intestine in a living or recently-killed animal, and
the other with the venous blood from the same part, an
effect occurs upon the needle indicating the secreted
product and the venous blood to be in opposite electric
states.

The amount of deflection of the needle would
vary according to the delicacy of the instrument
employed; with an ordinary galvanometer, consisting
of but few coils, the deflection was from 8° to 8°
or 10°.

When the electrode, instead of being in contact
with the venous blood, is in contact with the arterial
blood, or the surface of the mesentery, the effects
upon the needle are the same, as far as the direction
of the current is concerned, but the amount of
deflection may not be so great.

Let’ us now endeavour to explain these results
according to known actions, such as the chemical
reaction of two fluids upon each other, or to the
heterogeneity of fluids, as it is sometimes called. If,
for example, a glass cell be taken having a porous
diaphragm in its middle, such as a piece of mem-
brane, so as to divide it into two cells, and into one
compartment we pour an acid solution, and into the
other an alkaline solution, and then dip the platinum
electrodes of a galvanometer into each of these cells,
an effect upon the needle is produced indicating the
electrode dipping in the acid solution to be positive
to the other. These facts, which have been well
CHAP. IV. §.1. IN THE STOMACH AND INTESTINES. 31

worked out by BecquErEL2, may be enunciated in
the following proposition: During the reaction of two
fluids upon each other, that which performs the part of
an acid takes positive electricity, and that of an alkali,
negative electricity.

In experiments upon animals, as just related, it
was found that the electrode in contact with the
venous blood was positive to the other, excepting
when there was much acid in the stomach, and then
the electrode in contact with the mucous surface of
the stomach was positive to the other in contact with
the blood. Now in order to explain these results,
under the supposition that they arise from the
chemical reactions of the fluids upon each other, it
must be supposed, that when the electrode in contact
with the venous blood is positive to the other, that
then the blood acts as an acid, and not only so, but
combines with the substances of fluids in the in-
testines. When it is found, however, that the
electrode in contact with the stomach is positive,
then it may be supposed, and rightly so, that the
results are due to the chemical reactions which
occur in that organ between the acids and other
fluids that are there found. But should we be
justified in supposing, that when the electrode in
contact with the blood is positive to the other in the
stomach, the stomach being empty or containing
but little acid, that then the blood is acting as an
acid? Here, as in the intestines, it would be

8 Loc. cit. vol. ii. p. 77.
32 CURRENT FORCE. CHAP. Iv. §.1.

necessary to assume, that immediately after the
separation of the secreted product (the acid) from
the blood had taken place, that they then imme-
diately recombined; and not only so, but that the
blood, in direct opposition to the well-known fact of
its alkaline characters, must be acid in order to
account for the effects produced. It would there-
fore appear, that no grounds exist for believing that
the results obtained in the living animal can be
considered as entirely dependent upon the mere
reaction of the heterogeneous fluids upon each other,
upon their combination for example; and without
stopping to adduce more arguments against this
supposition, let us now proceed to compare the
results with another class of phenomena, viz. with
those actions which take place in a voltaic circle
where decomposition is effected.

It will be better to confine our attention to the
actions which take place in the exciting cell of a
voltaic circle where the power originates, and with-
draw our minds for the present entirely from the
changes which take place in the decomposing cell of
the battery where polar decompositions are effected :
the principal object being to ascertain whether,
during the decomposition of a compound, or during
the separation of an acid from an alkali, the same
effects are produced upon the galvanometer as
occurs during the combination of an acid with an
alkali.

Let us take an elementary circle, zinc, platinum,
CHAP. Iv. §.1. IN THE STOMACH AND INTESTINES. 33

and a dilute solution of muriate of soda, and con-
sider the two metals as forming the terminations
of the electrodes of the galvanometer, one of zinc
and the other of platinum, instead of having two
platinum electrodes as heretofore. When the elec-
trodes are dipped into the solution, the actions
which take place are the following: the muriate of
soda is decomposed by the attraction of the zinc
for the chlorine or muriatic acid, whilst the soda is
evolved on the surface of the platinum; now under
these circumstances the platinum electrode, in con-
tact with the soda, is positive to the other, and,
according to common phraseology, the direction of
the current is in the same direction as the cation
(the alkaline compound, the soda) is supposed to
travel, Here then is a case of decomposition, a
separation of an acid from an alkali, effected by
chemical agency, and the electrode in contact with
the alkali is positive to the other in contact with the
acid; the effect being contrary to that observed
during the combination of an acid with an alkali, as
has been just shewn. Let us now compare the
results which occur in the animal with those which
take place in the voltaic circle. When the electrode
is brought -into contact with the venous blood, it is
positive to the other in contact with the secreting
surface of the intestine; if it be now supposed that
the blood is alkaline, and there is every ground for
so doing, the electrode in contact with the blood is
exactly similar to that in contact with the alkali in
D
34 CURRENT FORCE CHAP. Iv. §. 1.

the voltaic circle; but instead of the secreted product
combining with the other electrode, as the acid does
in the voltaic circle, it passes away. In the animal
the current may be supposed to be dependent upon
the decomposition—if I may so term it—of the arterial
blood, being as it were separated into its two ele-
ments, the secreted product and venous blood, just
as the muriate of soda is decomposed and separated
into its two elements, muriatic acid and soda.

At present, it may be remarked, that no opinion
as to the mode in which the secretions are effected
is being given; I am only endeavouring to ascertain
now what does occur, and to what class of phenomena
these actions, those of secretion, bear the greatest
resemblance. This subject will again come under
our notice.

Before proceeding to shew that in other organs
there exists the same manifestation of current force
during secretion, I cannot omit noticing the opinion
that Woxtaston entertained in regard to the question
now under consideration, and shall therefore quote
his own words: “At the time,” says Woxzaston},
““when Mr. Davy first communicated to me his im-
portant experiments on the separation and transfer
of chemical agents by means of the voltaic apparatus,
which was in the autumn of 1806, I was forcibly
struck with the probability that animal secretions
were effected by the agency of a similar electric
power; since the existence of this power in some

» Philosophical Magazine, vol. xxxiii. p. 488.
CHAP. Iv. §.I. IN THE STOMACH AND INTESTINES. 35

animals was fully proved by the phenomena of the
Torpedo and of the Gymnotus Electricus; and since
the universal prevalence of similar powers of lower
intensity in other , animals was rendered highly
probable by the extreme suddenness with which
the nervous influence is communicated from one
point of the living system to another.

«And though the separation of chemical agents,
as well as their transfer to a distance, and their
transition through solids and through liquids, which
might be expected to oppose their progress, had not
then been effected but by powerful batteries; yet it
appeared highly probable that the weakest electric
energies might be capable of producing the same
effects, though more slowly in proportion to the
weakness of the power employed.

“ T accordingly at that time made an experiment
for the elucidating this hypothesis, and commu-
nicated it to Mr. Davy and to others of my friends.
But though it was conclusive with regard to the
sufficiency of very feeble powers, it did not appear
deserving of publication, until I could adduce some
evidence of the actual employment of such means
in the animal economy.

“The experiment was conducted as follows:
I took a piece of glass-tube, about three-quarters
of an inch in diameter and nearly two inches long,
open at both ends, and covered one of them with
a piece of clean bladder. Into this little vessel
I poured some water, in which I had dissolved
36 OURRENT FORCE cHaP. Iv. §.1.

ae of its weight of salt; and after placing it upon
a shilling with the bladder slightly moistened
externally, I bent a wire of zinc, so that while one
extremity rested on the shilling, the other might
be immersed about an inch in the water. By suc-
cessive examinations of the external surface of the
bladder, I found that even this feeble power occa-
sioned soda to be separated from the water, and
to transude through the substance of the bladder.
The presence of alkali was discernible by the appli-
cation of reddened litmus-paper after two or three
minutes, and was generally manifested even by the
test of turmeric paper before five minutes had
expired.

“ The efficacy of powers,” continues Wo.zasroy,
“so feeble as are here called into action, tends to
confirm the conjecture, that similar agents may be
instrumental in effecting the various animal secre-
tions which have not yet been otherwise explained.”

There is one circumstance connected with Wot-
LAsTOoN’s conjecture which must be noticed, viz. the
idea that secretion depended upon, or is the effect of,
a power similar to that which exists in a voltaic
circle; but it must be borne in mind, that the origin
of the power in the voltaic circle was not so com-
pletely understood at the time Woxtaston published
his conjecture as it is at the present day; and
although he himself was an advocate for the opinion
that it depended upon chemical action, it never-
theless required the elucidation that it has subse-
CHAP. Iv. §. 11. DURING BILIARY SECRETION. 37

quently received at Farapay’s hands; the fact being,
that the chemical action which occurs is the cause
of the power, or, in other words, the current is a
mere manifestation of the chemical action that is
taking place. I shall now pass on to the consi-
deration of the manifestation of current force during
secretion in other organs; and first, in the liver.

Sscr. II. On the Manifestation of Current Force
during Biliary Secretion.

If the platinum electrodes of the galvanometer be
inserted one into the gall-bladder, and the other into
the hepatic vein, or which will be found better still,
in consequence of the blood flowing over the in-
testines, into the vena cava ascendens in the chest, we
then obtain evidence of the manifestation of current
force; the electrode in contact with the blood in the
vein being positive to the other in contact with the
bile in the gall-bladder. The amount of deflection
of the needle varies from 5° to 10°.

When the electrode, instead of being inserted
into the hepatic vein or into the vena cava ascendens,
is inserted into the vena porta, the other remaining
in the gall-bladder, the former will still indicate a
positive state; but the effect upon the needle is not
so great.

Other circuits were formed; viz. between clots of
blood and pieces of liver; between the mucous
membrane of the intestines and the gall-bladder ;
between the blood in the chest and various parts of
38 CURRENT FORCE CHAP. Iv. §. II.

the abdomen; one electrode was coated with bile,
and then both of the electrodes were dipped into
the blood in the chest. It was generally found that
the electrode in contact with the blood was positive,
but not always; sometimes vibrations of the needle
only occurred, at other times the needle went as far
as 80° or 90°, and then stopped. The motions of
the needle presented quite a different character to
those observed when the bile in the gall-bladder
and the blood flowing from the vena cava inferior
were formed into a circuit; the latter presented a
steady character, they could be depended upon;
whereas with the former a greater effect might be
produced at first, and it would then cease, or perhaps
go in the opposite direction. The following con-
clusion may therefore be deduced: when the electrodes
of a galvanometer are brought into contact, one with the
bile in the gall-bladder, and the other with the blood in
the hepatic vein, or vena cava ascendens, an effect occurs
upon the needle, indicating the secreted product (the bile)
and the blood to be in opposite electric states.

It may be said, and with apparent justice, that if
the actions which occur during secretion be similar
to those that take place in the exciting cell of a
voltaic battery, as was suggested in the previous
Section, the electrode in contact with the alkaline
bile ought now to indicate a positive state.

The force of this objection depends entirely upon
the assumption that the bile contains a free alkali.
The researches of chemists, and especially Lresic,
CHAP. Iv. §. 1. DURING BILIARY SECRETON. 39

have however shewn, that with the alkaline bases
which exist in the bile, are associated peculiar
organic acids, such as the bilic, choleic, &. As these
acid compounds are easily decomposed, we should
not be justified in supposing, from finding a number
of indestructible basic elements which exist in the
ultimate analysis of the bile, that these basic ele-
ments therefore existed as such in the composition
of the bile; and although the bile may present
an alkaline reaction, this alone would not necessarily
indicate the existence of a free alkali. It would
appear more reasonable to suppose, that these basic
elements existed in combination with the destructible
organic acids. Similar remarks may undoubtedly be
made respecting the composition of the blood, but
the chemical evidence in favour of the existence of
a free alkali in the blood is far stronger than that
for its existence in the bile. The opinion that the
fluidity of the blood may be dependent upon the
alkaline salts has been long entertained by phy-
siologists, and would appear to have received strong
confirmation from the recent experiments of Dr.
Ricuarpsoni, to which I may refer.

Having so far removed this objection, the same
remarks that were made in regard to the secretion
that occurs in the intestinal canal, and which I need
not recapitulate, may now be applied to the formation
of the bile. So here in another class of secretions,

i The Cause of the Coagulation of the Blood. Churchill, 1858.
40 CURRENT FORCE CHAP. [v. §. 11.

additional evidence has been obtained of the mani-
festation of current force during secretion.

Before passing on to other secretions, I shall now
notice.the fallacy of supposing that the stomach and
liver form poles similar to those of a galvanic battery,
an idea that has been entertained by several indi-
viduals. No evidence could be obtained to shew
that the stomach forms the positive and the liver the
negative electrode of a circuit similar to those of a
voltaic circle. It may just as well be supposed, that
the lungs and the stomach, or the lungs and the
kidneys, or the liver and the lungs, or the kidneys
and the lungs, are similarly related, if we are to be
guided by the mere circumstance of their relative
connections in regard to the circulation of the blood
through these different organs. Hach organ, the
stomach and liver, would appear to have, however,
its own elementary circle, if I may so express it;
but no evidence exists to shew that these two organs
are so mutually related as to form one circle. There
is one fact which is of some interest, and deserving
of notice, it is this; the blood, from which the biliary
secretion is formed, has previously undergone some
most important changes during its passage through
the coats of the stomach and intestines, and thus an
important relationship must necessarily exist be-
tween these two organs; and the question may
naturally arise, Is not the blood during its passage
through the coats of the stomach and intestines, and
especially by the stomach, thus deprived of most of
CHAP. Iv. §. 111. DURING URINARY SECRETION. 41

the elements of its fixed acids, such as the muriatic
acid for example, and so far accounting for the small
proportion of these elements that are found in the
bile? It must be observed, that I am not now
supposing that all the acids found in the stomach
must necessarily come from the blood, for there can
be no doubt that some of the acids are formed in
that viscus independent of those that are secreted by
that organ. But to enter upon this subject would
carry us away from our main object, and I shall
therefore leave it.

Secr. III. On the Manifestation of Current Force
during Urinary Secretion.

Upon inserting one of the extremities of the
electrodes of the galvanomeier into the pelvis of the
kidney, and the extremity of the other electrode into
the renal vein of the same kidney, an effect upon the
needle is produced indicating the electrode in con-
tact with the blood to be positive to the other. A
difficulty may sometimes arise in obtaining any
effect. The amount of deflection of the needle,
when obtained, varies from 8° to 5°.

Should we be justified, in this instance, in sup-
posing that the blood is acid to the urine, and not
only so, but combines with the urine, in order to
account for the effects observed upon the galva-
nometer, when a more satisfactory explanation can
be adduced, by regarding the effects as being con-
sequent upon the separation of the acid product from
42 CURRENT FORCE CHAP. IV. §. III.

the blood, as already advanced in the previous
Sections with respect to the other secretions?

The amount of deviation of the needle being
small, may be referred to the same causes as were
observed to exist with regard to the acid secretions
and fluids in the stomach. The secretion, urine,
being acid, counter currents arise and are produced
by the reaction of the acid of the urime upon
the fluids and substances with which it comes
into contact. In judging, therefore, of the effects
upon the needle, we must take into consideration
the acting points in the circuit; there may be at
least three acting points in a circuit, viz. at the
point of secretion, and at each of the electrodes. If
the direction of the current consequent upon secretion
coincide with those that occur at the electrodes, then
an increased effect upon the needle is necessarily
produced; but if these currents tend to go in oppo-
site directions, then the result upon the needle will
be merely the differential effect. Hence we should
be led to very erroneous conclusions, judging merely
from the effect upon the needle, either as to the
Jorce of the current, or its origin.

Sufficient evidence has been obtained to warrant
the following deduction, viz. that when the electrodes
of a galvanometer are brought into contact, one with the
urinary secretion and the other with the venous blood
from the same part, an effect upon the needle occurs
indicating the blood and the urine to be in opposite
electric states.
CHAP. Iv. §. TIL. DURING URINARY SECRETION, 43

It may just be remarked, that slight effects may
be observed when the electrode is in contact with
the arterial blood instead of the venous blood, the
other being in contact with the urine. But no
effects are obtained when one electrode is inserted
into the vein and the other into the artery of the
kidney.

Whilst upon the subject of urinary secretion, I
may allude to a circumstance of some interest. At
the time the original experiments were performed,
it was frequently observed that the blood continued
to indicate its positive condition, long after the
secreting process could have been going on, which
led to the belief that the blood might have the
power of retaining its peculiar electrical state. Sub-
sequent experiments have tended to confirm this
opinion, but it was never supposed that the secretions
could have the power of retaining their peculiar
electrical condition until lately. Reading over some
of the Memoirs published at the time of the cele-
brated controversy between Gatvanr and Vorta, I
was much gratified by accidentally finding a letter
written by Vassatt Hanoi, at that time one of the
celebrated Professors at Turin, to M. DELAMETHRIE,
then Secretary to the Royal Academy of Paris, who
requested his opinion “ upon Galvanism and the origin
of Animal Electricity,” and to which I have referred
in chap. i. The position these two individuals
held might be adduced as giving some weight to
their authority. Amongst other arguments that
44 CURRENT FORCE CHAP. Iv. §. Iv.

Vassatt Eanpr brings forward in favour of the
existence of Animal Electricity is the following:
“J'ai prouvé ailleurs,” says Vassatt Hanp1, “ que les
urines donnent une électricité négative, et j’ai fait
voir plusieurs fois aux D. Gerri, Garortr et aux
éléves de médecine et de chirurgie, que le sang tiré
des veines donne dans mon appareil électrométrique
(décrit dans le Vol. Ve de l’Académie des Sciences de
Turin, Dec. 19, 1790) une électricité positive.”

It need scarcely be stated, that the galvanometer
was not then known, and that the effects observed
by Vassar HEanpt were those of attraction and
repulsion. Although the results obtained by Vassatz
Eanpr may be supposed to be due to other circum-
stances than those arising from Animal Electricity,
such as evaporation or chemical action, nevertheless,
as recorded facts, they are of some value, inasmuch
as they tend to establish similar conclusions which
have been arrived at by different modes of investi-
gation, and entirely independent of each other.

Szor. IV. On the Manifestation of Current Force

during Mammary Secretion.

In my original paper only one experiment was
recorded, as shewing the results that were obtained
in the Mammary gland; since then, several other
opportunities have occurred in which similar results
were observed.

If we insert the electrodes, one into a lactiferous
vessel and the other into a vein from the same part,
CHAP. Iv. §.IV. DURING MAMMARY SECRETION. 45

the electrode in contact with the vein is positive to
the other 8° or 10°.

Here, in this instance, we get evidence of the
secreted product (the milk) and the venous blood being
im opposite electric states.

It will now be seen, from the foregoing expe-
riments, that wherever secretion occurs, whether in
the stomach and intestines, in the liver, in the
kidneys, or in the mammary gland, it will be found
that the act itself is not only accompanied with the
manifestation of current force, but that the venous
blood is also, in all these instances, in the same
state, in a positive electric state. The next question
that would naturally arise is the following: What is
the state of the arterial blood? Although it has
been found that the arterial blood indicates a positive
state when formed into a circuit with the secreted
product, the other necessary element, viz. its electro-
negative element, the cation, for example, has not yet
been obtained. Reasoning from analogy, it is in
the lungs that a satisfactory explanation on this
point must be sought for. —

Physiologists may not perhaps be disposed to
admit that the function of the lungs corresponds to
that of a secretory organ; or that the process by
which carbonic acid is eliminated from the blood

_ corresponds to that by which the acid is eliminated
from the stomach; fortunately a decision on this
point will not be necessary, and therefore need not
46 CURRENT FORCE CHAP. IV. §. v.

detain us. One circumstance, however, is well
known, viz. that carbon, in some form or other, is
eliminated from the blood during its passage through
the lungs; and it may so happen, that during the
elimination of this carbon, its separation from the
venous blood whilst traversing the lungs, that
current electricity becomes manifested.

Sect. V. On the Manifestation of Current Force
during Respiration.

When one electrode is brought into contact with
the mucous membrane of the bronchial tubes, and the
other inserted into the left ventricle of the heart, the
latter electrode is positive to the former from 2° to 5°.
When the electrode, instead of being inserted into
the left ventricle was inserted into the right ventricle,
it still indicated a positive state. Here then are
indications of the arterial blood being positive to the
mucous surface of the lungs: how far this state may
be due to the separation of the carbon from the venous
blood which traversed that organ may be a subject
of dispute; the fact, however, is of some importance,
as indicating the electric condition of the arterial
blood.

In looking back upon the results that have now
been obtained, some surprise may be felt at the
circumstance, that all these experiments tend to
indicate that, during life, the blood, whether venous
or arterial, is in a positive electrical state or con-
CHAP, Iv. §. V. DURING RESPIRATION. 47

dition, and that this state or condition is partly
produced and maintained by the various secretions
that take place in the animal body. How far the’
fluidity of the blood, and the vitality of the blood, as
it is called, are dependent upon this electric state or
condition, are questions which must necessarily
arise in our minds. The particles of the blood,
also, must under these circumstances exist in a state
of self-repulsion: and may not this fact, it may be
asked, tend to explain some of the phenomena
connected with the circulation of the blood in parts
not dependent upon the vis a tergo action of the
heart, and also those connected with the coagula-
tion of the blood when taken from the living
animal? Before concluding this Section let me
just observe, that a clue has now been obtained to
the non-appearance of any effect upon the galva-
nometer when the two electrodes are inserted into
an artery and a vein, a point previously established by
the experiments of Povirtet and Mutier*. As the
blood in the two vessels is in the same electric state,
no effect could occur upon the needle; thus proving
the fact, well established by Farapay, that in order
to obtain cuRRENT FoRcE, the circuit form must be
given to the arrangement, i.e. that the electrodes must
be brought into contact, or by means of some conducting’
mass, with the ANION and CATION originating the power}.

There are one or two points which must now be
noticed. It may be supposed, first, that the effects

E Loe. cit. 1 Experimental Researches, vol. ii, p. 51.
- BP
48 CURRENT FORCE CHAP. Iv. §. Vv.

that have been obtained may arise from thermo-
electric actions, since BrcquErEL™ and BrescHer
have ascertained the existence of a difference in
temperature between the arterial and venous blood
by means of a galvanometer; secondly, that they
may also arise from the actions that take place upon
the surface of the platinum electrodes. We will
now notice these objections.

First, as to catalytie actions, or the combining power
of platinum. There are strong experimental reasons
for believing, that when blood escapes from a wound,
it enters into combination with the oxygen of the
atmosphere; when a plate of platinum therefore is
in contact with the blood, actions similar to those
which occur in the gas-battery take place. We have
aright to suppose that similar actions would occur
at the other electrode, namely, that in contact with
the bile; still, it might not necessarily follow that
the latter would counteract the effects of the former.
Judging then from the direction of the current, the
effects may be fairly supposed to be due to the
actions which occur between the atmosphere and
the blood, or, in other words, to catalytic actions.

There can be no doubt that the effects observed
are partly due to catalytic actions; and we may even
go further and say, that they must be so as a necessary
consequence. Just now it was necessary to suppose
the, blood to be actd—to contain an anion—to account
for the effect; now we are obliged to suppose it to

™ Loe, cit, tom. vii. p. 20.
CHAP, IV. §.V. NOT DUE TO THERMO-ELECTRIC ACTIONS, 49

contain a cation—to be alkaline—to account for the
catalytic action, or if not in an alkaline state, still in
such a state as to combine readily with the oxygen
of the atmosphere. Now this latter state we are
necessarily driven to entertain, when supposing,
which no physiologist will deny, that the blood,
during secretion, undergoes a change similar to that
of decomposition®,

Secondly, as to Thermo-electric actions. Buc-.
QUEREL® and Brescuet, as is well known, have shewn
that different parts of a living animal are of different
temperatures; but it must be borne in mind, that
their experiments were intended to elucidate thermo-
electric actions, and might not, therefore, be re-
garded as comparable with the present. Although
it would be “considered rather a stretch of the
imagination to suppose that the effects can be
referred to thermo-electric actions, since no effect
was obtaineil when the electrodes were inserted into
the vena porta and hepatic veins, as in former
experiments, or even in the experiments of MuLLzEr,
between the corresponding arteries and veins, still,
it is for physiologists to shew that the effects cannot
be referred entirely to these actions. To assist in
deciding this question, the following experiments
were undertaken.

A porcelain jar, 2 inches and a half in diameter

~ It is not necessary to point out in what manner, whther
by parent-cells or secreting-cells.
° Traité de l'Hlectricité, tom. vii. p. 20.

E
50 CURRENT FORCE CHAP. Iv. §.v.

and the same in depth, capable of holding about five
ounces and a half of fluid, was used as the external
cell; a portion of the small intestines of a rabbit,
eapable of holding half an ounce of fluid, was
suspended by threads, and formed the internal cell ;
the ends of the electrodes, to the extent of half an
inch, were bent at a right angle, and placed in each
cell, the other extremities being connected with the
galvanometer and mercurial cups, as in the experi-
ments on animals. Thus arranged, water at dif-
ferent temperatures was poured into each cell.

Experiment 1. é
Temperature of atmosphere .. . Tl
Temperature of water in external cell 68
Temperature of water in internal cell 120

Slight vibrations of the needle. Lvery endeavour to
obtain a greater effect failed. The temperature of
the fluid in each cell was then ascertained by means
of a delicate thermometer.

Temperatnre of internal cell . . . 105
Temperature of external cell . . . 80
Experiment 2. ‘
Temperature of external cell . . . 160
Temperature of internal cell . . . 68

Vibrations as before; and it was then found that the

°
Temperature of external cell was . 125
Temperature of internal cell . . . 98
CHAP. IV. §.V. NOT DUE TO THERMO-ELECTRIC ACTIONS. 51

Experiment 3. -

Temperature of external cell . . . 67

Temperature of internal cell . . . 180
Vibrations; and

Temperature of external cell . . - 81

Temperature of internal cell . . . 110

In whatever manner the experiments were varied,
whether by using water at greater or less differences
of temperature, similar results were obtained. The
vibrations were sharp and quick at the commence-
ment, but soon terminated; in no instance could
a decided effect upon the needle be obtained by
making and breaking contact, and the effects were
not in any way similar to those observed in the
animal body. “There is one remark, however, which
might be made in reference to these experiments,
viz. if the two fluids could be kept at constant tem-
peratures at the point of contact, more decided effects
might be expected.

In the following experiments a resistance—a liquid
conductor—was added to the circuit, to see if the
current would be capable of traversing it. A glass
tube, nearly half an inch in diameter and 3 inches
in length, was bent thus, U, and contained water ;
one limb was connected with one of the mercurial
cups by a piece of copper wire of the same thickness
as those connected with the galvanometer, ,and
3 inches in length; the other limb of the tube was
connected with another mercurial cup by a similar
52 CURRENT FORCE CHAP. IV. §.v.

piece of copper wire; each of these wires dipped, to
the extent of a quarter of an inch, into the water.
We thus had a resistance consisting of a column of
water, nearly half an inch in diameter, 2 inches and
a half in length, and 6 inches of copper wire. By
this arrangement the current could be made to
travel through the galvanometer, with or without the
resistance, at pleasure, by merely dipping the elec-
trodes into one mercurial cup or the other, and
without any loss of time.

Experiment 1.—Rabbit. Pithed. Between renal
vein and bladder; with resistance, vibrations; without,
3° or 4°: with, vibrations; without, vibrations.

Between left bronchus and left ventricle; with
resistance, no effect; without, 4°: with, 2° or 3°;
without, no effect.

Between gall-bladder and blood from vena cava
inferior; with resistance, 5°; without, 8°: with, 5°;
without, 10°. The motion of the needle with the
resistance was slow and steady.

Experiment 2.—Rabbit. Pithed. Between right
bronchus and left ventricle; without resistance, 2° or
3°; with, vibrations: without, vibrations.

Between gall-bladder and blood from vena cava
inferior; without, 10°; with, 8° or 4°: without, 10°.

Between renal vein and bladder; no effect either
with or without the resistance.

I will not attempt to deduce any conclusions
from these experiments as to the force of the current,
but leave it for the physical philosopher to decide
CHAP IV. DURING SECRETION. 53

whether the effects can be entirely due to thermo-
electric actions. But there can be no doubt that a
part of the effects may be referred to these circum-
stances, and partly also to catalytic actions, and they
must therefore be taken into consideration when
judging of the final result upon the needle.

The results recorded in the present chapter tend
to establish the following conclusion, viz. that the
act of secretion in the living animal is accompanied with
the manifestation of CURRENT FORCE; and the phe-
nomena, with which this act of secretion appears to
be the most intimately related are those that oceur
in the voltaic circle. A difficulty may arise to some
minds in perceiving this relation, from the cireum-
stance that in the ordinary voltaic circle metals are
employed. If we bear in mind that the metals,
although one of them is usually acted upon, serve
principally as conductors, and that they are not
essential for the developement of the power, this
difficulty will be easily removed. Now as the mani-
festation of current force during the actions which
occur in the voltaic circle are considered as evidence
of polar action, there can be no reason why it should
not be so considered in regard to organie action,
viz. during secretion; but before we arrive at this
conclusion, let us compare the phenomena of secretion
with another class of facts, viz. with those of osmose.

Professor Granam has communicated a very valu-
able Paper to the Royal Society, entitled, On Osmotic
54 CURRENT FORCE CHAP. IV.

Force, which has since appeared in their Trans
actions?. In this Paper Professor GraHam has shewn
that osmose is dependent upon chemical action, and
not, as it has been generally supposed, upon capillary
attraction. Space will not allow me to enter upon
the facts brought forward in support of this opinion ;
and I must therefore refer my readers to the Paper
itself, which cannot be too strongly recommended.

The conditions under which an osmotic experiment
is conducted, viz. the necessity of having two fluids,
one on each side of the septum, render it extremely
difficult to ascertain by means of the galvanometer
the exact mode of action which arises during osmose,
so as to compare it with that which takes place in
the animal body during secretion, in consequence of
the reaction of the two fluids upon each other pro-
ducing their own peculiar effects on the galvanometer ;
and the changes upon which osmose depends take
place, according to Professor Granam, within the
substance of the porous diaphragm, where we cannot
apply the electrodes of the galvanometer.

The fact of osmose depending upon chemical
action, shews however that the act itself must not be
considered as a mere transudation, a mere physical
separation, but that it depends upon other important
conditions; and if upon chemical action, they are
consequently polar in their nature. If this con-
clusion be arrived at in regard to osmotic phenomena,
we may with equal propriety consider the phenomena

P Phil. Trans. 1854.
CHAP. Iv. DURING SECRETION. 55

connected with secretion to be at least something
more than a mere physical transudation; and as
reasons exist for shewing that osmotic phenomena
are polar in their nature, why may we not also
consider the action connected with secretion, and
where we can obtain such direct evidence of polar
action as manifested by the galvanometer, to be
polar in its nature?

Respecting the chemical character of osmose, and
its bearings upon physiology, Professor Gnranam
adds: “It may appear to some that the chemical
character which has been assigned to osmose takes
away from the physiological interest of the subject, in
so far as the decomposition of the membrane may
appear to be incompatible with vital conditions, and
osmotic movement confined therefore to dead matter.
But such apprehensions are, it is believed, ground-
less, or at all events premature. All parts of living
structures are allowed to be in a state of incessant
change—of decomposition and renewal. The de-
composition occurring in a living membrane, while
effecting osmotic propulsion, may possibly be of a
reparable kind. In other respects, chemical osmose
appears to be an agency particularly well adapted to
take part in the animal economy.”
CHAP. V.

ON THE MANIFESTATION OF CURRENT FORCE DURING
LACTEAL ABSORPTION 4,

From the results that have been detailed in the
last chapter, I was naturally led to suppose, that’
during lacteal absorption some evidence might be
obtained of the manifestation of current force; since
an identity between this process and secretion has
been long recognised by physiologists. MuzEr’
says, ‘absorption (lacteal) seems to depend on an
attraction, the nature of which is at present un-
known, but of which the very counterpart, as it were,
takes place in secretion; the fluids altered by the
secreting action being repelled towards the free side
only of the secreting membranes, and then pressed
onwards by the successive portions of fluid secreted.”

~ My original Papers, on the Developement of Current Force
during Lacteal Absorption, Nutrition, in the Muscular and the
Nervous Tissues, and in Plants, were communicated and read
before the Royal Society in 1852. It being decided that they
should not be published in the Transactions, they were ordered
to be placed in the Archives of the Society. Upon wishing to
refer to these three Papers two years afterwards, they were
missing from the Archives of the Society, and were ultimately
found to be in the hands of the referee!!!

> Elements of Physiology, translated by Baly, 2nd edition,
vol. i. p. 801.
CHAP. V. CURRENT FORCE DURING LACTEAL ABSORPTION. 57

The experiments were performed upon cats,
guinea-pigs, and rabbits; young cats will be found
to be the best subjects. After the animal had been
kept without food for some hours, a large quantity
was then given to it, and the experiment performed
at different periods, from a quarter of an hour to an
hour, or longer, after the food had been taken.
According to the time that elapsed between the
meal and the experiment and the previous empty
state of the stomach, so could the lacteals be traced
out in various parts of the intestines; and it was
interesting to observe the marked contrast between
the empty portions of the gut, and that portion
where digestion was going on; the difference in the
vascularity of the parts being so very great. One
electrode being inserted into the intestine, and the
other in contact with the chyle flowing from a
lacteal coming from the same part, the latter was
positive 8° or 10°. The effects were just the same as
if the electrode had been in contact with the blood
from a vein from the same part as described in the
last chapter.

Now it may be said, and with some justice, that
these results are evidently due to secretion; that they
are the identical experiments that have been related
in the last chapter, the only difference being, that
the force is conducted by the mesentery. In reply
to this it may be stated, that those effects, instead’ of
being referred to secretion, may be considered as due
to lacteal absorption.
58 CURRENT FORCE CHAP. V.

To decide this point, let us just observe we have
two facts before us. First, the venous blood in-
dicates a positive condition; and, secondly, the chyle
also indicates a similar state. Now if any difference
exists between these two fluids, we shall detect it by
inserting the electrodes, one into the vein, and the
other into a lacteal; but upon doing so no effect°
occurs upon the needle. This experiment is the very
counterpart to those of Pourtter and MvuLuEr, when
they inserted the electrodes into the vein and artery
of a living animal without observing any action upon
the galvanometer, and to which I have already alluded.
This negative result would only prove that the chyle
and the venous blood are in the same electric states ;
and all that can be said in regard to the experiments
we are now considering is this, that the effect,
the positive state as indicated by the needle, may be
due partly to the positive state of the chyle, and
partly to that of the venous blood which is conducted
by the mesentery.

From what has been already remarked in regard

© It must not be supposed that no effect is always obtained
under these circumstances. It is difficult and almost im-
possible, in these physiological experiments, not to obtain some
slight effect upon the needle; but any one, after a little
experience, would even be enabled to ascertain the marked
difference between u decided and definite action upon the
galvanometer, due to a definite and permanent cause, and that
which might arise from some slight and variable circumstance,
such as u difference in the state of the parts as regards
moisture, and as to the contents of the intestines, &c.
CHAP. V. DURING LACTEAL ABSORPTION. 59

to the acids in the stomach, it may be readily sup-
posed that in this viscus the same effects would be
observed as in the former experiments; viz. that the
current dependent upon the acid secretions would
overcome and mask any effect that might arise from
lacteal absorption.

Sufficient evidence, I think, has been adduced to
prove the following conclusion, viz. that during lacteal
absorption the absorbed product (the chyle) and the
substances from which it is absorbed (the food) are in
opposite electric states. The conditions necessary for
the manifestation of current force are complete; we
can trace out the anion and cation of the circuit,
the former in the food, the latter in the chyle; we
have no reason to believe that the chyle is acid in
order to account for the effects, for all chemical
analyses tend to shew its alkaline condition; and
I need not repeat the arguments employed in the last
chapter in regard to the supposed acid condition of the
blood, for the purpose of accounting for the effects as
they are applicable on the present occasion. I
would not go so far as to say that acids are never to
be discovered in the chyle or in the blood; for it is
possible that in some morbid states of the system
this circumstance might occasionally happen.

I am not now attempting any explanation as to
the mode by which lacteal absorption takes place or
is brought about, whether it is to be considered as a
mere case of imbibition, or as a case of osmose. I
am only shewing that during this act current force is
60 CURRENT FORCE. CHAP. V-

manifested, and that consequently it is a polar
phenomenon. Perhaps it would be as well for the
present to consider it as an organic act, and it may
be looked upon as a case of organic endosmose, whilst
secretion, on the other hand, may be considered as a
case of organic exosmose.
CHAP. VI.

ON THE MANIFESTATION OF CURRENT FORCE DURING
NUTRITION. IN THE MUSCULAR TISSUE. IN THE
NERVOUS TISSUE.

I wave now arrived at a point of my subject which
has unfortunately been a source of some dispute and
bitter controversy; into this, however, it will not be
necessary for me to enter: and as my chief object
will be to point out the origin or cause of the
principal effects observed, rather than to give an
elaborate and detailed account of all the facts that
have been obtained, I shall not go so fully into the
subject as might be expected, but endeavour to be
as concise as possible, not omitting any thing of
importance.

The question, whether Nutrition is accompanied
with the manifestation of Current Force, will be
considered under two heads. first, in regard to the
Muscular Tissue; and secondly, in regard to the
Nervous Tissue.

Szor. I. On the Manifestation of Current Force during
Nutrition in the Muscular Tissue.

I have already alluded to the circumstance in

chap. i. that so far back as 1827, Nort, in some
62 CURRENT FORCE CHAP. VI. §.1.

experiments undertaken for the purpose of ascer-
taining the comparative sensibility of the galva-
nometer and the galvanoscopic frog, found, that
when the frog’s limb was so arranged that the
feet were placed in one vessel containing water, and
the lumbar nerves in another vessel, then upon
completing the circuit with the galvanometer an
effect was produced upon the needle indicating a
current to pass from the feet to the upper part of
the limb; the electrode in the vessel containing the
nerves being positive to the other. This he called
the proper current of the frog, a term by which it is
designated at the present day, and he considered
that the effects were thermo-electric in their nature.

Marrevccr subsequently pursued the subject, and
amongst other most important results he ascertained,
that when a muscle was divided and one electrode
placed in contact with the divided surface, and the
other in contact with the external surface, an effect
was produced upon the needle. He further shewed,
that this effect depended upon the vital condition of
the muscle, upon the state of its nutrition.

After the publication of Marrsucci’s earlier ex-
periments, Du Bois Reymonp took up the subject,
and from a series of ingenious experiments deduced
what he designated as the law in regard to the
muscular current, viz. that any point of the longitudinal
section or the surface of the muscle was positive to
any portion of the transverse section, whether natural
or artificial, of the same muscle. Finding, however,
OHAP. VI. §.1. IN THE MUSCULAR TISSUE. 63

that this law does not hold good in its entire gene-
rality, that the current was not always obtained when
the so-called natural transverse section (viz. the
tendon) and the longitudinal section were formed
into a circuit, he was led to suppose that a layer,
which he denominated the para-electronomic layer,
exists, and which might fully account for the occa-
sional non-appearance of the current. For my own
part, I have never been able to satisfy myself of the
existence of this layer or its necessity; but there can
be no doubt about the fact, that when the divided
surface or artificial transverse section and the longi-
tudinal section or surface are formed into a circuit,
that then the so-called muscular current is obtained.
Previous to any knowledge of Du Bois Reymonp’s
researches, I was led, from the results that I had
already obtained in regard to secretion, to believe, that
if the tissue, the muscular, was formed into a circuit
with the venous blood, I might perhaps obtain
some evidence of ‘a current, as I had already done
in regard to secretion. Iwas further strengthened
in this supposition, by finding that Marrgucctr
explained the results he had obtained by repre-
senting the muscular fibre as similar to a zinc plate
in a voltaic circle. He says, ‘‘ We must never forget
the analogy between the muscular electro-motor
element and the voltanian element: the zinc is
represented by the discs of the muscular fibre, the
acid liquid by the blood, the platinum by the sarco-
lemma. Whatever be the conducting body with
64 CURRENT FORCE CHAP. VI. §. I.

which the zinc is made to communicate with the
platinum, the current is always in the same direc-
tion...... The chemical actions of nutrition evolve
electricity4.” It has always been a source of great.
surprise to me, that Marrruccr has never attempted,
as far as I am aware, to ascertain the correctness
of this opinion or the result of the experiment, viz.
that of forming a circuit between the muscular fibre
and the blood, as it was the only evidence required
to prove his conclusion.

I now performed the experiment in the following
manner. Laying bare the muscles of the animal at
the upper and inner part of the thigh, one electrode
was inserted into the substance of the muscle, or,
which is better still, placed in contact with the
divided transverse section of the muscle, and the
other electrode was inserted into the blood flowing
from a neighbouring vein; a slight effect occurred
upon the needle indicating the blood to be positive.
If the electrode be placed on the external surface
of the muscle instead of its divided surface, the effects
are doubtful. If both electrodes were in contact,
one with the divided surface of the muscle and the
other with its external surface, then the latter elec-
trode was positive to the former; the result being the
so-called muscular current. That the effects should
be null or difficult to be obtained when the external
surface of the muscle and the venous blood are
formed into a circuit, need not be surprising, since

4 Philosophical Transactions, 1845, p. 801.
CHAP. VI. §.1. IN THE MUSCULAR TISSUE. 65

the positive state of the surface of the muscle prevents
that of the blood from becoming manifested, these
two parts, in fact, presenting the same electric con-
dition.

I need not relate other experiments: proving the
conclusion, that we can obtain evidence of current
force being manifested when the muscular tissue
and the venous blood are formed into a circuit.
The effects, it is true, are but small, but nevertheless
definite; and the question now arises, can they be
referred to nutrition ?

Although it may ‘perhaps be difficult at first sight
to see that the effects can be referred to nutrition,
nevertheless, when we bear in mind the strong
resemblance that exists between secretion and
nutrition, this apparent difficulty will be removed.
Nutrition differs from secretion in this; in nutrition
the secreted product (the tissue) remains behind,
and is not carried off as in ordinary secretion. Not
only does the tissue (the secreted product) remain
behind, but it also retains its peculiar electric
negative state, and may be considered as the gnion
of the circuit, whilst the cation exists and passes on
in the blood. The electric state is not only pro-
duced by nutrition, but maintained by it. We have
no right to suppose that the blood is acid in order to
account for the effects; and it would appear, according
to Lizsre’s researches, that lactic acid is developed in
the muscular tissue.

I am not going so far as to suppose that nutrition,

F
66 CURRENT FORCE CHAP. VI. §. I.

as it takes place in the muscular tissue, is so rapid a
change as may occur in some of the secreting organs,
that the tissue is deposited and immediately taken
up again, or constantly undergoing changes; I am
far from supposing this, and do not pretend to be
able to trace out the exact changes that take place,
nor the time that is required to effect these changes.
We have, however, under any point of view, to
consider how this electric condition of the tissue is
brought about, and what other circumstance, I may
ask, is more likely than nutrition? We have a vera
causa at work, and such a one as is likely to produce
the very result observed. I may also refer to the
results obtained by Marrevcci, in which he has shewn
the dependence of the current (muscular) upon the
state of the tissue in regard to its nutrition, that what-
ever influences the latter affects the former. At the
same time, I am perfectly aware that objections may
be raised to his mode of conducting the experiments,
viz. by forming piles of animal substances, but
I cannot help thinking that these objections may be
carried too far.

It may be asked, and with some justice, how can
we account for the external surface of the muscle
being positive to the divided transverse surface? we
can understand, it may be said, the cation existing
in the blood producing its positive state, but where is
the cation in the external surface ?

I shall allude to this question in a future chapter,
when it will again come under consideration ; and as
CHAP. VI. §. 1. IN THE MUSCULAR TISSUE. 67

I am now going to state some conclusions, the proof
of which have not yet been presented to my readers,
I must refer to this chapter for the requisite evidence.
My chief object now is to shew, that nutrition is
accompanied with the manifestation of current force ;
and the fact that the tissue is in an electric state,
may be considered as a corollary to this conclusion.
The current (muscular) therefore may be considered
as existing under two points of view: jirst, when the
tissue and the blood are formed into a circuit, the
current, then manifested, is due to the act of nutrition,
it continues during nutrition, whilst the changes are
going on, just as the current is manifested in the
voltaic circle during the time that the chemical
changes are taking place: secondly, when the external
and divided surfaces are formed into a circuit, then
the effects resemble those of a charged Leyden jar
rather than those of a voltaic circle. The tissue
itself being negative, and what is more was deposited
as such during nutrition, the external surface, the
sarcolemma, becoming positive by induction.

Before passing to the consideration of the nervous
tissue, I think sufficient evidence has been adduced
to warrant the following conclusion, viz. that during
nutrition in the muscular tissue, the muscular fibre and
the venous blood are in opposite electric states.
68 CURRENT FORCE CHAP. VI. §. I.

Seor. II. On the Manifestation of Current Force during
Nutrition in the Nervous Tissue.

Dv Bors Reymonp was the first to shew that the
nervous fibre, like the muscular fibre, presented an
electrical condition; the external or longitudinal
surface being positive to the divided surface, pro-
ducing the so-called nerve current, when the two
surfaces are formed into a circuit with the galva-
nometer.

The results that I had obtained in regard to the
muscular tissue led me to make inquiries respecting
the nervous tissue; and for this purpose, after
having exposed the brain, I inserted one of the
electrodes into the substance of the brain, and the
other into the internal jugular vein; the effects
upon the needle were very decided and manifest.
The needle advanced from 10° to 20° or more, the
electrode in contact with the blood being positive to
the other in the brain.

Marteucci® relates some experiments performed
by MM. Pacinorri and Puccinorm, and by himself,
in which the electrodes were inserted one into the
brain, the other into the muscles, He says, “La
deviation obtenu dans la premiére immersion a été
dirige du cerveau aux muscles dans l animal.
Liintensité du courant est trés-variable: j’ai obtenu
quelquefois 80° et méme davantage, et quelquefois
10° & 15°, et toujours dans la premiére immersion.”

© Traité des Phénoménes Electro-Physiologiques, p. 121.
OHAP. VI. §. IL. IN THE NERVOUS TISSUE. 69

The object of these experiments was, I believe, for
the purpose of ascertaining whether any electric
current traversed the nerves. I shall have occasion
to allude to them again in a subsequent chapter.

Why the effects should, be so decided in this
instance, when compared to those that are observed
in muscles, may arise from the greater mass of the
brain, and to the circumstance of the blood coming
directly from it, and thus the conditions may be
better adapted: to shew the effect, than when the
muscle and vein were formed into a circuit in the
thigh. If the experiment be performed with the
sciatic nerve, placing one electrode in contact with
the divided surfacé, or the external surface, and the
other. in contact with the blood coming from the
vein of the nerve, then the effects are similar to
those observed with the muscles. Repeating Du
Bors Reymonp’s experiment, viz. forming the divided
and external surfaces into a circuit, the same result
was obtained, the external surface was positive to the
other; but the effects were not so great as when the
same parts of a muscle were formed into a circuit ;
nevertheless the effects were decided and definite.

I need not repeat the arguments that were used
respecting the blood being acid, in order to account
for the effects; and with regard to the external
surface of the nerve being positive, to the divided or
transverse section; this may be considered as due to
the same circumstance as was observed with the
muscular fibre, viz. the positive state being induced
70 CURRENT FORCE. CHAP. VI. §. II.

by the negative condition of the nerve fibre. I may
just remark, that the very fact of the muscular and
nervous tissue presenting the same results, would
tend also to confirm the opinion, that they are
evidently due to one and the same cause, viz.
nutrition; and I think sufficient evidence has been
adduced to shew, that the nervous tissue and the blood
(venous) are in opposite electric states.

Before quitting this part of my subject, I cannot
too strongly urge the necessity of constantly bear-
ing in mind the importance of attending to the
circumstances under which the current is manifested
in these two tissues, the muscular and the nervous;
and as I have just before alluded to this point
when speaking of the muscular current, I must refer
to the remarks there made, as they will be found
applicable to our present case, to that of the nerve
current.
CHAP. VII.

ON THE ELECTRIC CONDITION OF THE BLOOD.

“SHovLp any physiologist,” says Munir, “ be so
fortunate as to prove beyond doubt the electric
property of the blood, I could only congratulate
Science on the great advance which it would thus
have made*.” From these observations of MuLLER
it would appear, that up to his time no satisfactory
conclusions had been arrived at in regard to this
question.

From the experiments related in the previous
chapters, besides the conclusions then drawn in
regard to the manifestation of current force during
secretion and nutrition, we may also deduce the
following conclusions as corollaries.

First, That the blood, both venous and arterial, while
circulating in the animal body, is in a positive electrical
state; and,

Secondly, That this electrical state is produced and
maintained by the secretory, respiratory, and nutritive
actions. .

Now these conclusions which have been arrived
at as corollaries to other conclusions go far to prove

a Muller’s Physiology, translated by Baly, 2nd edition, vol. i.
p- 148.
72 ELECTRIC CONDITION OHAP. VIL.

the experimental results obtained by VassaL1 Hanp1,
and to which I have already referred’. To him,
therefore, must the credit be given, as having been
the first to establish the important fact, ihe electric
condition of the blood by experimental evidence.
That his experiments should have been overlooked,
or even passed by as undeserving of attention, is
somewhat remarkable; and I can only refer it to
that injudicious scepticism, too frequently expressed
where a knowledge of the subject is wanting, and
sometimes from other motives, which is as great a
bane to the progress of science, as the opposite evil
a too easy credulity.

Although objections may be raised to the expe-
rimental results obtained by BELLINGERI as recorded
by Mouuuzr, he nevertheless appears to have arrived
at, the conclusion, that arterial and venous blood
presented no difference in regard to their electrical
properties; and that the electrical property of the
blood is preserved long after its abstraction from
the vessels.

There can be no doubt that most important
phenomena are connected and associated with this
electric condition of the blood; that a great many
of its properties, which have been referred, in conse-
quence of being inexplicable, to a vital condition,
belong to it. Its particles must be in a state of self:
repulsion, and may therefore assist in the circulation
of the blood. Some of the peculiarities connected

> Chap. i.
OHAP. VII. OF THE BLOOD. 13

with the coagulation of the blood are no doubt also
dependent upon it; but as these are questions which
require special investigations for their solution, I shall
merely allude to them, and observe, that the subject
presents to any inquirer an ample field for future
discoveries, important to the pathologist as well as
to the physiologist.
CHAP. VIII.

ON THE ELECTRIC CONDITION OF THE MUSCULAR AND
NERVOUS TISSUES. MUSCULAR CURRENT. NERVE
CURRENT. POLARIZED CONDITION OF THE MUSCULAR
TISSUE AND OF THE NERVE TISSUE.

In chap. vi. besides the conclusion that current
force was manifested during nutrition in the mus-
cular and the nervous tissues, and that the tissues,
the muscular and the nervous, presented one
electric state, the negative, whilst the venous blood
presented the other condition, the positive; it was
also shewn, from the experiments of Marreuccr and
Du Bors Reymonp, and confirmed by some of my
own, that similar effects were obtained when the
external and divided surfaces, either of the muscle
or of the nerve, were formed into a circuit producing
the so-called muscular and nerve currents, the ex-
ternal surface in both instances being positive to the
divided or transverse section. The question natu-
rally arises as to the origin of the current; we can
understand the negative state being produced during
nutrition, the tissue in fact being deposited as the
anion, whilst the cation is passing away in the blood ;
but, it may be asked, where is the cation on the
external surface? Martreuccr®, in some of his recent

4 Bibliothéque Universelle de Genéve, &c. 1856.
CHAP. VIII. MUSCULAR AND NERVOUS TISSUES. 75

researches, appears to entertain some difficulty in
considering what really is the true electro-motor
element of the circuit. under these circumstances.
I have already suggested, that the muscular tissue
and the nervous tissue may be considered in the
same light as a charged Leyden jar; that the positive
condition of their external surfaces may be caused
by induction, the tissue itself being negative, and
deposited as such during nutrition. Before we can
come to this conclusion, however, it will be necessary
to investigate the subject more fully.

For the convenience of discussion, I may just sum
up, in a few propositions, the results which appear
to be well established by the researches of Matrrrucct
and Dv Bois Reymonp, and such as I have been
enabled to confirm by my own experiments, which
it will not be necessary to particularize.

1. Any point of the surface of a musele is positive in
relation to any point of the divided or transverse section
of the same muscle.

2. Any point of the surface of a nerve is positive in
relation to any point of the divided or transverse section
of the same nerve.

These two propositions express the law as deduced
by Du Bots Rermonp in regard to the muscular and
the nerve currents. ;

Dv Bors Reymonp has, however, applied the terms
natural and artificial to the different sections. There
may be no objection to the employment of these
terms; but unfortunately the so-called natural
76 ELECTRIC CONDITION OF THE CHAP. VII.

transverse section may act as the surface or longi-

tudinal section in regard to the artificial section or

the divided surface; and I do not think that the

existence of the para-electronomic layer can be suf-

ficiently made out, to account for the difference of
effect which may thus occur to justify us in employ- ,
ing these terms; nevertheless, I perfectly agree with

Dv Bors Reymonp, in considering that the side or

external surface, or perhaps the sarcolemma of the

muscle, and the base or ends of the muscular fibre,

are the important points to be in contact with the

electrodes for the production of muscular current,

and the similar parts in the nerve for the production
of the nerve current.

3. The intensity of the muscular and nerve current
depends upon the vital conditions of the tissues;
the current does not subside immediately. after the
death of the animal, and evidently bears some re-
lation to the state of its nutrition.

4, According to Marrevectr®, the intensity of the
muscular current varies as the length of the muscle
in the circuit, and not according to the extent of its
transverse section. This proposition is, however,
rather difficult to prove; for, if two muscles of the
same length, but of different thicknesses, be formed
into a circuit, the thicker muscle will be found to
give the more intense current, (and the same will be
found in regard to the nerve;) and I cannot help
thinking, that Du Bors Reymonp is correct in con-

b Loe, cit.
CHAP. VIII. MUSOULAR AND NERVOUS TISSUES, 77

cluding that the electro-motive force of. muscles
increases both with their length and thickness.

5. If the two ends—the divided or artificial trans-
verse sections—of a muscle or of a nerve be placed
between the electrodes of a galvanometer, no effect
occurs upon the needle; but if one of the electrodes
be placed upon the surface or longitudinal section,
the other remaining in contact with the transverse
section, the current is produced according to the
law expressed in Proposition I.

6. If the electrodes be placed upon two symme-
trical portions of the surface of the muscle or of the
nerve, no effect is produced upon the needle.

The following experiments were now performed :
A muscle or nerve was divided into three or more
portions, and then so arranged that the internal
should form the outer portions, the continuity of the
nerve being maintained. When the electrodes were
placed at the two extremities, or upon symmetrical
portions of the nerve or muscle, no effect, or, if any,
but very slight indications were occasionally pro-
duced upon the needle; if the external surface and
the divided surface were formed into a circuit, the
current was obtained; and also when the portions
were so arranged, that the external surface of one
portion was placed in contact with the transverse
section of another, then the current was obtained, as
in Marreuccr’s. experiment, when forming a pile of
muscular elements. These experiments, which I
78 ELECTRIC CONDITION OF THE CHAP. VIII.

consider of some importance, were repeated several
times upon the muscles and nerves of frogs, guinea-
pigs, and rabbits; care being taken to have the
portions of nerve and muscle, as far as possible, of
the same size, and from the same nerve or muscle.
They go far to shew, that the muscular or nerve fibre
does not indicate any manifestation of polarity in
regard to its length; there is no fact or evidence of
any kind to shew either that the nerve fibre or the
muscular fibre presents a condition at one extremity
opposed to that of the other extremity; there is no
antithetical or dual condition made manifest indi-
cative of polarity; whatever indication of polarity
exists, shews it to be manifested in the transverse
direction, or rather that the muscular fibre or nerve
fibre presents one condition, and perhaps the sarco-
lemma or the neurilemma the other; and we are now
brought to the consideration of our original question,
Can this state be dependent entirely upon the
changes which occur during nutrition? And where
is the cation? Or can we suppose the sarcolemma
or the neurilemma to act as an acid? or might not
the effect (the current) be due to the electrical
condition of the muscular or nerve fibre, its negatively
electric state being maintained so long as the vital
conditions of the tissue continue ?

Under the supposition that the effects might be
due to the heterogeneity of the parts, the sarcolemma
or the neurilemma acting as an acid, I now repeated
the experiment, employing the following dilute
CHAP, VIII. MUSCULAR AND NERVOUS TISSUES. 79

solutions :—Five drops of strong sulphuric acid to
one ounce of distilled water, formed the acid solution;
one drachm of liq. potasse (Phar. Londin.) to one
ounce of distilled water, formed the alkaline solution ;
and one drachm of common salt to one ounce of
distilled water, formed the neutral solution.

Whenever one electrode was moistened with the
acid solution, this was positive to the other on what-
ever parts of the muscle or nerve they were placed.
When both electrodes were moistened with the so-
lution, the indications were doubtful.

When the alkaline solution was employed in the
same manner, the electrode in contact with the
external surface of the muscle or nerve was positive
to the other; it very rarely happened that the elec:
trode in contact with the tranverse section indicated
a positive condition, when the other electrode alone
was moistened with the solution.

With the solution of salt, similar effects were
observed as with the alkaline solution; and from
these facts we cannot but infer that these two
solutions, the alkaline and the salt, acted merely as
a conducting liquid, whilst the acid solution acted
chemically upon the animal substances. It cannot
be supposed, or at any rate be believed, that the
sarcolemma or neurilemma acted, in these instances,
as an acid substance, merely for the purpose of
explaining or accounting for the existence and di-
rection of the current, since the alkaline solution
would have destroyed its acid reaction.
80 ELECTRIC CONDITION OF THE OHAP. VIII.

When the muscles and nerves had been placed in
strong concentrated solutions, so as to act chemically
upon the tissues, and different portions of them
were then formed into circuits, the effects upon the
needle were sometimes very powerful, sometimes
null; the results, however, could never be predicated,
and were evidently due to the chemical-actions set
up.

If the muscle or nerve was placed in hot water at
the temperature of 180°, or in cold water at the
temperature of 32°, so as to freeze it, the musele or
nerve current was seldom obtained.

If the muscle or nerve was squeezed up into a
mass, so as to destroy its structure by mechanical
means, no effect at all analogous to that of the mus-
cular or nerve current was obtained; effects upon
the needle were occasionally produced, but pre-
senting quite a different character.

These results only tend to prove the conclusions
already deduced by Marreuccr and Dv Bors Rey-
MoND, of the dependence of the muscular and nerve
current upon the normal or vital condition of these
two tissues, and go far to shew, that these currents
cannot be entirely due to the heterogeneity of the parts
in the circuit, but that whatever destroys the normal
or healthy state of the tissues, destroys also the
conditions upon which the muscular or nerve current
depends.

Tf the existence of the muscular and nerve currents
be dependent entirely upon the changes which occur
CHAP. VIII. MUSCULAR AND NERVOUS TISSUES. 81

during the act of nutrition, it is reasonable to suppose
that the removal of the blood from the limb might
perhaps prevent them from being manifested. I was
now led to the following experiments :

The animals—guinea-pigs, rabbits, and frogs—
were bled to death, and the limbs and muscles
then emptied, as far as possible, of the blood, by
squeezing the limbs; under these circumstances the
muscular and nerve currents were obtained. The
amount of deflection was not perhaps so great as it
would have been had the blood not been removed;
nevertheless, the current was manifested. I en-
deavoured to remove the blood by injecting water
(at the temperature of 90° in the guinea-pigs and
rabbits, and at the temperature of the atmosphere
for the frogs) into the blood-vessels; and although
the water escaped by the veins, still the current was
obtained, amounting from 2° to 5° in the muscles,
and from 1° to 2° in the nerves. The muscles in
these latter experiments became turgid, but they
were not so pale as might have been expected;
and I very much doubt whether the blood was
entirely removed from the limb or the muscular and
the nerve tissue. These latter experiments, as far as
they go, would tend to shew the importance and
dependence of the current upon nutrition; and al-
though, in absence of further evidence, it would be
impossible for us at present to state, or even con-
jecture, the period at which the act of nutrition ter-
minates, there nevertheless appears to be a residual

@
82 POLARIZED CONDITION OF THE CHAP. VIII.

effect in these results which cannot be fully accounted
for, under the supposition that the current is due
entirely to the changes which occur during nutrition ;
and I believe that we shall be justified in coming
to the following conclusions, and in considering
that the so-called muscular and nerve currents may
depend upon three circumstances: jirst, upon the
changes which occur during nutrition ; secondly, upon
the heterogeneity of the parts, (including under this
term the action of the platinum electrodes, viz. the
catalytic action or the combining power of platinum
upon the moist animal substances in contact with its
surface ;) and, thirdly, upon an electrical state or
condition of the muscular or nerve fibre itself.

In thus considering the muscular or nerve fibre as
being in a peculiar state or condition which may be
termed polarized®, an objection might be urged to
the employment of this term, inasmuch as the term
polarity embraces the idea of duality—an antithetical
action, which, as we have seen, does not exist in

© Dr. Todd, I believe, was the first to describe the true cha-
racter of the phenomena I am now speaking of, and to point
out their dependence upon nutrition, and also to consider them
as being polar in their nature. See the article on the Physiology
of the Nervous System in the “ Cyclopedia of Anatomy and
Physiology.” Du Bois Reymond speaks of the tissue as being
in an electro-tonic state. I have avoided using this term electro-
tonic, as the facts appear to me to resemble those of a charged
Leyden jar, rather than that of a wire conducting a current of
electricity.
CHAP. VIIC. MUSCULAR AND NERVOUS TISSUES. 83

regard to the fibre itself. It is therefore necessary
to point out with what class of phenomena the facts
appear to be the most nearly allied.

Nutrition, I believe, may be referred to the same
class of actions as secretion, the tissue, muscular or
nerve tissue, being deposited as a secreted product.
These actions, secretion, I have already considered
as identical with those which occur in the decomposing
cell of a voltaic circle, and to be Pozar in their
nature. The question, however, whether the secreted
product and the blood can, when separated, maintain
their peculiar electrical states I have not yet ex-
amined; but in regard to the. blood, I believe that
that fluid may, from what I have occasionally ob-
served in my former experiments, and confirmed as
they are by the results obtained by Vassatr Hanp1.
At any rate, the improbability of the elements of
compounds undergoing decomposition in a decom-
posing cell of a voltaic circle, retaining their
peculiar electrical states, would be no positive
argument against this supposition; the state and
condition of the liquids in animals, in regard to
their fluidity, and the conditions under which the
changes occur, present great differences compared to
those that take place in ordinary voltaic decom-
positions; consequently, it may be reasonably sup-
posed, that under the circumstances in which the
changes occur in the animal body, the electrical states
of the solids and fluids are not immediately lost.
From these facts, I feel no difficulty or hesitation in
84 POLARIZED CONDITION OF ‘THE CHAP. VII.

regard to the origin of the muscular or of the nerve
current in the experiments we have been lately con-
sidering, viz. when the two surfaces of a muscle or
of a nerve, the transverse section and the eaxternal
surface, are formed into a circuit. During nutrition,
the tissue is deposited as an anion, the cation passing
on in the blood; the negative electric condition of
the tissue is maintained by nutrition, and continues
in that state; it may, perhaps, be looked upon as
being in a state of tension, polarized; and when the
muscular or nerve fibre, and any other part—for
instance, the sarcolemma or the neurilemma—are
formed into a circuit, an effect is produced upon the
needle, indicating the existence of a current. Under
these conditions, the results become analogous or
are identical with those that are observed with a
charged Leyden jar, when the inner and outer
surfaces are formed into a circuit; the tissue being
negatively electrized may, perhaps, render the sarco.
lemma or neurilemma positive by induction‘.

In speaking, therefore, of the fibre as being in
a polarized condition, it would lead to erroneous
views if we supposed that one portion, taking its
longest diameter, was positive or negative to the other,

4 This positive condition of the external surface will go far
to explain a circumstance which at one time rather perplexed
me. When the external surface of a muscle, and the venous
blood flowing from it, were formed into a circuit, the effect upon
the needle was but slight; the external surface of the muscle
and the blood being both positive, will fully account for the
feebleness of the current then manifested.
CHAP. VIII. MUSCULAR AND NERVOUS TISSUES. 85

as a wire may be supposed to be when traversed by
an electric current; the fibre would appear rather
to represent an excited glass rod, as far as its mode
of action may be considered, rendering other parts
electric by induction; but whether the force exists
of that intensity to produce attraction or repulsion,
would appear doubtful after the experiments of
Vassatt Eanpre. It does not necessarily follow
that, because the current is produced, attraction and
repulsion should also be obtained; the intensity
requisite in the one case may be absent in the other;
and I cannot do better than refer to the important
Paper, by Farapay, on the Gymnotus‘, for the pur-
pose of pointing out the great difference manifested
in the two instances in regard to animal electricity
and machine electricity. But the conditions under

e The following experiments of my own may, perhaps, be of
some interest. The limbs of frogs were suspended by means
of a silk thread to a glass beam, which was also suspended
horizontally by a silk thread attached to its centre, and fastened
above to another glass rod. Upon holding a silk thread near to
the limb, no attraction or repulsion of the thread was observed.
Exciting a glass rod, and presenting it to the limb, the limb
was powerfully attracted; it was attracted also upon presenting
an excited stick of sealing-wax to it. But I never obtained any
effect, when one limb was presented to the other, either of
repulsion or attraction; it would appear as if one of the sub-
stances must be in an excited state to produce these phenomena.
I do not consider these experiments of much value, and not at
all adapted to eliminate any very correct result; but they tend
to indicate the negative character of the tissue.

f Experimental Researches, vol. ii. p. 1.
86 POLARIZED CONDITION OF THE CHAP. VIII.

which the muscular or the nerve current may occur
will be of the utmost importance to bear in mind:
whether as the act of nutrition, or during nutrition ;
or whether as the result of nutrition, 2. e. from the
polarized condition of the fibre itself, since they may
be referred to two distinct classes of actions. Their
primary dependence, however, upon nutrition is a
circumstance of some importance; and it would
appear that this polarized condition of the tissue
is intimately connected with the so-called vital con-
dition of the parts; the irritability of the muscular
fibre and the sensibility of the nervous tissue being
perhaps dependent upon it.

As the constituents of a muscle or its particles
must be in a state of self-repulsion, the electrized
or polarized condition not being limited to the
surface, as in a metallic conductor, but the whole
substance of the muscle throughout being equally
and bodily polarized, the question arises, Might not
muscular contraction be the necessary result of the
attraction between the particles, the muscular sub-
stance being, as it were, depolarized by nervous agency;
and the force by which the state of tension in the
muscle was maintained being evolved and set free
or made manifest in some other form or mode of
action, according to circumstances? In a future
chapter we shall see that some evidence has been
obtained, indicating that, during extraordinary mus-
cular exertion, some force is evolved, as in the fish;
but during ordinary muscular exertion, the force may
CHAP, VIII. MUSCULAR AND NERVOUS TISSUES. 87

not become free, but be exerted in some other
manner, as heat&.

Before concluding, although I have alluded to the
subject in chap. i., it may be remarked, that we are
now brought to the consideration of the explanation
of Gauvani's celebrated experiment, viz. the con-
traction that ensues when the nerve is brought into
contact with the external surface of the muscle.
GALVANI compared the muscles to a charged Leyden
jar, the two surfaces, the external and internal, being
in opposite electric states; and he considered that
when the circuit was completed, the contraction was
@ necessary consequence of the passage of electricity
from one surface to the other by means of the nerve.
No one can deny that Ganvani was so far correct;
he erred in considering the electricity as secreted in
the brain, and transmitted by the nerves to different
parts of the body, the muscles serving as mere
reservoirs of the electricity; overlooking the fact,
pardonable at his time, that electricity might be
developed in other parts as well as in the brain.
Votta erred in denying the origin of the power in
the animal body, but was correct in pointing out
that similar effects could be obtained by other means

8 Dr. Radcliffe has published some views in regard to muscular
contraction, in which he considers the muscle as being the seat.
of “ polar action,” and contraction as the result of molecular
attraction. I cannot do better than refer to the Paper for the
arguments upon which his conclusions are founded, which will
be found published in the Medical Times and Gazette, June,
1855.
88 POLARIZED CONDITION OF THE CHAP. VIII.

than with organic substances; the essential condition
in all these experiments being, that the current
should traverse the nerve, the effect—the muscular
contraction—remaining the same, whether the cur-
rent had its origin in the animal body, or from
arrangements formed external to the body, and in-
dependent of it. Voura’s experiments appear to
have been adapted for the purpose of ascertaining
the effect of current electricity upon the animal body;
Gatvant's, for the purpose of ascertaining the origin
of the effects that were observed to occur in the
animal; and whatever views he might have enter-
tained in regard to the nerve force being édentical
with ordinary electricity, all subsequent experiments
only tend to shew the great difference that exists
between these two agents,—the action of current
electricity, and that of nerve force. In saying this,
however, I am very far from denying that nerve force
is a polar force, and consequently it must bear some
relation or connection with the other polar forces;
nerve force being, as Dr. Topp has pointed out, a
higher form of polar force, and perhaps the highest
form that we are acquainted with; and being such,
we may reasonably suppose that its chief and perhaps
peculiar polar characteristics can become manifested
in the animal body alone. In another chapter this
question will again come under consideration.

The following conclusions in regard to the origin
of the so-called muscular and nerve currents may
be deduced from the foregoing experiments:
CHAP, VIII. MUSCULAR AND NERVOUS TISSUES. 89

First, They may depend upon the changes which
occur during nutrition.

Secondly, They may depend, also, upon the hetero-
geneity of the parts; (including under this term the
action of the platinum electrodes, viz. the catalytic
action or combining power of platinum upon the
moist animal substances in contact with its surface ;)
and also,

Thirdly, Upon a polarized condition of the nerve or
muscular fibre.

Fourthly, That this polarized condition of the fibre
is produced and maintained by nutrition. And,

Fifthly, That the circumstances under which the
current may be produced may resemble, in one
instance, those arising from the changes which occur
in the decomposing cell of a voltaic circle; and in
the other, those that arise from the action of a
charged Leyden jar. In the latter case, the current
being due to the polarized condition of the fibre;
in the former, to the changes which occur during
nutrition.
CHAP. IX.

ON THE POLARIZED CONDITION OF THE MUSCULAR AND
OF THE NERVOUS TISSUE IN THE LIVING OR RECENTLY
KILLED ANIMAL. MUSCULAR FORCE AND NERVE
FORCE, POLAR FORCES.

Havine arrived at the conclusion, in the last
chapter, that the muscular and nervous tissues are,
during life, in a peculiar electrical state or condition,
and which has been termed polarized, the following
question naturally arises, Can this state, dependent
as it evidently is upon nutrition, be increased by any
artificial means? That it may be diminished or
easily destroyed is to be inferred from the fact, that
whatever interferes with the proper nutrition of a
muscle or nerve, or disorganizes their structure,
whether by mechanical or chemical agencies, destroys
also the conditions upon which the existence of the
muscular or nerve currents depends; and it is, it
may be observed, from the manifestation of these
currents that the existence of this polarized con-
dition is inferred. It is reasonable, therefore, to
suppose, that it might be by the employment of the
electric force (or current) that we should perhaps
obtain some evidence to assist in solving this
problem.

In considering the question of the influence of
electricity upon the muscular and nervous tissues,
CHAP. IX. MUSCULAR AND NERVOUS TISSUE. 91

we are necessarily brought to the examination of the
various experiments that have been undertaken from
the period of Gatvant’s celebrated discovery up to
the present time, in which muscular contraction has
been induced by means of the agency of electricity
upon the nerves. On the present occasion, however,
as it is by means of the galvanometer rather than by
muscular contraction alone that the evidence proper
for the solution of our question might be obtained,
it will not be necessary to enter into a critical review
of the various results made known to us by our
predecessors; but I shall state those facts in the
form of a few propositions which appear to have
been well-established by the labours of Voxra,
Marianini, Nopit1, Marrreucct, Marsaatt Hat,
Du Bors Reymonp, and others’, and to which I shall
have occasion to allude in the course of the inquiry.

lst, When an electric current traverses a nerve, it
is only at the opening and closing of the circuit that
muscular contraction ensues.

2dly, No muscular contraction occurs during the
passage of the current.

8dly, After the inverse current has passed for some
time along a nerve, upon opening the circuit, tetanic
contractions are produced; with the direct current no
tetanic contractions take place.

> In Becquerer’s Traité de l’Electricité, will be found an
account of the views of the earlier inquirers, and also some
very valuable observations of his own in regard to animal

electricity. I may also refer to De 1a Rive’s Treatise on
Electricity, translated by Walker.
92 POLARIZED CONDITION OF THE CHAP. IX.

The question may now arise, Can the muscular
contraction of a limb be considered as evidence of an
increase of the polarized state or condition of the
nerve going to that limb? Previous to considering
this question, let us endeavour to ascertain whether
any increase occurs in the muscular or the nerve
current under these circumstances.

Marranini®, under the supposition that electricity,
in these experiments, accumulated in the tissues,
says, “En appliquant avec soin les fils du galva-
nométre aux fibres palpitantes ou aux nerfs adhérens,
on pourrait, peut-étre, détourner en partie ces
courans, et les faire passer par le galvanométre;
mais les expériences que j’ai faites Jusqu’a présent
sur ce point aussi délicat ne me permettent pas
encore de rien affirmer avec assurance.”

Marrevccr® adds, “ How is this tetanic action
produced? It is easy to convince one’s self, if any
doubt could be entertained upon the subject, that
there is no electricity rendered latent either in the
nerves or in the muscles by the passage of the inverse
current. My endeavours to discover signs of any,
by the aid of the condenser, have been entirely
fruitless. Likewise there are no signs, on opening
the circuit, of any electric current in circulation.
I have made myself quite certain of this fact by
means of the galvanometer, employing at the same
time a pile of tetanized frogs.”

b Annales de Chimie et de Physique, tom. lvi. p. 887, 1884.
© Phil. Trans. ]848, part ii. p. 286.
OHAP, IX. MUSCULAR AND NERVOUS TISSUE. 93

In the following experiments, the current either
from 1, 3, or 6 of Grove’s middling-size cells was
passed through a detached muscle, or a portion of
the sciatic nerve, the platinum electrodes being so
arranged, that the anode or platinum extremity was
in contact with the base or transverse section of the
fibre, and the cathode or zinc extremity in contact
with the external or longitudinal surface ; the direction
of the current being in accordance with the normal
direction of the muscular or nerve current, or that
which is called the inverse current. The muscle or
nerve, which was from rabbits, guinea-pigs, and
frogs, was placed upon two pieces of glass, separated
from each other, so that the current should traverse
the substance of the tissue; but how far it was
conducted by the surface and not by the fibre alone,
may be a question difficult to decide.

The normal effect of the muscular or nerve current
was first ascertained and noted; the former amount-
ing to 4° or 5°, the latter to 2° or 3°, depending,
however, upon the state of the nerve or muscle, and
also of the animal. The current from the battery
was allowed to pass along the fibre for different
periods of time, when the effect upon the muscular
or nerve current was then examined,

The effects, generally speaking, were as follow:

With the current from one cell, after it had passed
five minutes, the amount both of the muscular and
nerve current was slightly diminished; after ten
minutes, the nerve current was not obtained, the
94 POLARIZED CONDITION OF THE CHAP. IX.

muscular current still existed; fifteen minutes, no
nerve current, nerve dry, muscular current but slight;
twenty minutes, no effect; twenty-five minutes, no
effect.

With the current from three cells, after five
minutes, the nerve current very slight, the muscular
current somewhat diminished; after ten minutes, no
nerve current, nerve dry, muscular current slight ;
fifteen minutes, no effect from nerve, muscular
current very slight; twenty minutes, no effect from
either; twenty-five minutes, no effect.

With the current from six cells, after five minutes,
no nerve current, nerve dry, muscular current very
slight; after ten minutes, indefinite indications of
the needle with the nerve, no muscular current;
fifteen minutes, no effect with nerve, with the
muscle the current occasionally indicated a reversed
direction ; twenty minutes, no effect with the nerve,
indefinite indications of the needle with the muscle;
twenty-five minutes, effects similar to those last
observed.

As no distinct evidence of an increase either in the
muscular or nerve current was obtained, it has not
been thought necessary to particularize the results.
Great care was taken in all these experiments to
depolarize the platinum electrodes after the com-
pletion of each circuit, and to have them well
cleaned.

In the next series of experiments, the current was
passed direct, so as to traverse the fibre in the con-
OHAP. IX. MUSCULAR AND NERVOUS TISSUE. 95

trary direction to that of the muscular or nerve
current. As the results did not indicate any increase,
or even any decided diminution in the muscular or
nerve current, and were in many respects similar to
those I have already related with the inverse current,
they need not be detailed.

Employing litmus paper to test the indications of
the two surfaces of the fibre in contact with the
electrodes, the effects were the same; there was no
distinct acid or alkaline deposit on either of the two
surfaces. The tissues soon became dry.

The results in all these experiments, after the
current had passed for some time through the nerve
or muscle, and especially when more than one cell
was employed, evidently arose from the electro-
chemical actions set up in the moist animal sub-
stances, by means of the electric current employed
destroying the conditions necessary for the existence
of the muscular or nerve current, and setting up new
actions. It is extremely doubtful whether the cur-
rent traversed the fibre’; it might have been con-
ducted by the surface alone; and, in considering the
action of the current upon the tissue, it is not diffi-
cult to perceive that its effect (its mode of action)
would be not that of increasing the electrical state of
the tissues, but more of a disorganizing action. What
is evidently required is, to induce the negative elec-
trical state of the fibre, which constitutes its polarized

4 Marrevccr believes that the current is conducted by the
liquid part of the nerve. Phil. Trans. 1850, p. i. p. 888.
96 POLARIZED CONDITION OF THE CHAP. IX.

.condition; and it does not appear that, by merely
passing a current through it, we should be able to
produce the effect we wish.

Instead of a constant, an intermitting current, from
an ordinary medical electro-magnetic machine, was
employed, and made to traverse the muscular or
nerve fibre as before. In these instances, there was
no indication of an increase in either of the muscular
or nerve currents.

The limbs of a galvanoscopic frog were now placed
in separate glass vessels, employing the current from
the battery of six cells, the current being inverse in
one limb and direct in the other, as in Matreuccr’s
experiment. When tetanic contractions were pro-
duced in the inverse limb, an attempt was made to
ascertain whether any difference existed between the
muscular and nerve currents of both limbs. No
decided difference between the two limbs could be
detected ; differences were occasionally observed, but
the nerve current in the direct limb was apparently
as frequently increased as that of the inverse limb,
but the muscular and nerve currents of both limbs,
and in other parts of the same frog, generally indi-
cated a greater amount of deflection previous to the
passage of the current from the battery than afterwards.

It may be asked, Do not these tetanic contractions
indicate an increase in the polarized state or con-
dition of the nerve? Dv Bois Reymonp‘ states,

© On Animal Electricity. Edited by H. Bence Jones, M.D.
p. 218.
CHAP. IX. MUSOULAR AND NERVOUS TISSUES. 97

that he has obtained indications of an increase in the
nerve current, by passing an electric current along
a portion of the same nerve. He says, “ If any part
of a nerve is submitted to the action of a permanent
current, the nerve, in its whole extent, suddenly
‘undergoes a material change in its internal con-
stitution, which disappears on breaking the circuit
as suddenly as it came on. This change, which is
called the electro-tonic state, is evidenced by a new
electro-motive power, which every point of the whole
length of the nerve acquires during the passage of
the current, so as to produce, in addition to the
nerve current, a current in the direction of the
extrinsic current. As regards this new mode of
action, the nerve may be compared to a voltaic pile,
and the transverse section loses its essential import.
Hence the electric effects of the nerve, when in the
electro-tonic state, may also be observed in nerves
without previously dividing them.”

The experiment was repeated in the following
manner :—Platinum wires, connected with the gal-
vanometer, were placed in contact with the two
portions of the nerve, (the longitudinal and the trans-
verse sections,) so as to obtain the nerve current.
The current from one, three, or six of Grove's
middling-sized cells was then passed along another
portion of the nerve, at different distances from that
portion connected with the galvanometer, the elec-
trodes of the battery being pointed. When the
current from the battery was confined to a small

H
98 POLARIZED CONDITION OF THE CHAP. IX.

portion of the nerve, and at some distance (an
inch or more) from the other portion, it very
rarely happened that I could obtain any effect
upon the nerve current. When the electrodes
of the galvanometer comprised half-an-inch of the
nerve, and the electrodes of the battery also the
same extent, and were not far from those con-
nected with the galvanometer, then an effect was
frequently produced upon the nerve current; the
effect, however, was, generally speaking, that of a
decrease in the nerve current, and this took place,
whatever might be the direction of the current from
the battery, whether coinciding with, or in opposition
to, the direction of the nerve current. It very
seldom happened that an increase in the nerve
current was obtained; and, as these results were
chiefly observed to occur when more than one cell
was employed, the effects—the apparent increase,
and perhaps the decrease, of the nerve currrent—
may be more correctly referred to some disturbance
in the position of that portion of the nerve between
the electrodes of the galvanometer, arising during
the passage of the current in the other portion; an
tmerease occurring when the nerve pressed against
the electrodes, and a decrease when it separated from
them. It may be just remarked, that the nerves
soon became dry in these experiments.

The nerves were taken from the frog, guinea-pig,
and rabbit.

Similar results were obtained when muscles
CHAP, IX. MUSCULAR AND NERVOUS TISSUES. 99

were employed in the same manner for the pur-
pose of ascertaining the effect upon the muscular
‘current.

Although the effects observed may partly arise
from an alteration in the contacts of the twe surfaces
of the nerve between the electrodes of the galva-
nometer, I nevertheless believe, with Du Bots
Reymonp, that the passage of an electric current in
another portion of the same nerve is capable of
affecting the conditions upon which the nerve
current depends; but I have not been so fortunate
as Du Bois Reymonp in obtaining such decided and
definite evidence as could have been wished in regard
to the increase of the nerve current. In all these
experiments, the distance of the electrodes, both of
the galvanometer and battery, from each other, and
the extent of the nerve between each of the elec-
trodes, and also the state of the nerve in regard to
the dryness of its surface, are points of the utmost
importancé to be considered and attended to in
judging of the final result.

The only conclusions that can be deduced from

the foregoing investigations are the following:
‘1st. That we have no evidence of being able to
increase the polarized condition of the nervous and of
the muscular tissue by artificial means, such as the
electric current; but it is highly probable,

2nd, That an increase of this polarized condition
may arise from an increased action of those changes
which take place in the living animal, such as
100 POLARIZED CONDITION OF THE CHAP. IX.

nutrition, being the same means by which it is pro-
duced and maintained.

Before acceding to these conclusions, it may be
reasonably asked, Have we not other evidence,
besides that afforded by means of the galvanometer,
to indicate an inerease in the polarized condition of
the nerve? Do not the tetanic contractions, which
are observed in a limb whose nerve has been sub-
jected to the action of an electric current (inverse),
indicate an increased action of the nerve?

A current from six of Grove’s cells was passed
through the limb of a galvanoscopic frog in the
inverse direction, and as soon as tetanic contractions
were produced, the nerve was divided at the junction
of the nerve with the muscles of the limb; the
tetanic contractions ceased. The two ends of the
divided nerve were now placed in apposition, but no
tetanic contractions ensued. This inverse current
was again allowed to pass for some time through the
nerve thus united, but no tetanic contractions oc-
curred upon the breaking of the circuit. Great care,
however, is required in this experiment to divide the
nerve at the exact point where it emerges from the

- muscles, as pointed out by Marreucct, otherwise the
tetanic contractions take place.

The results of this experiment only tend to con-
firm what has been already satisfactorily proved by
others, that the continuity of the nerve fibre in the
nerve leading to the muscle is necessary for the
conduction of the impression excited at the distal
CHAP. Ix. MUSCULAR AND NERVOUS TISSUES. 101

end of the nerve, in order to arouse muscular con-
traction. It need scarcely be added, that the mus-
eular and nerve currents may, however, be obtained
under these circumstances between the separated
portions. .

The results of these investigations lead to the con-
clusion, that the muscular and the nervous tissues
are both, during life, in a polarized state or condition,
and from our inability to inerease this state by any
artificial means, it being produced and maintained
by nutrition, would almost stamp it as being peculiar
to the organic kingdom. All the experiments tend,
moreover, to shew, that it must be by acting upon
and employing the means by which it is produced
and maintained, viz. through the act of nutrition,
that we can hope to succeed; and it is reasonable
to suppose, that whatever would increase this act
would also increase this condition, as shewn by an
increase in the muscular and nerve currents under
these circumstances. That tetanic contractions may
be produced by means of the electric current upon
the nerve, might perhaps be adduced as an argument
in favour of the supposition that an increased action
.of the nerve is produced, and, consequently, an
‘increase in the polarized condition; but how far the
peculiar state of the nerve which produces tetanic
constructions under these circumstances is due to an
increase of the normal polarized condition is question-
able, as I shall endeavour to point out.

When an electric current from a voltaic circle or
102 POLARIZED CONDITION OF THE: QHAP. IX«

any other source traverses a nerve or muscle, the
muscle or nerve forms a part of the conductor; as any.
other moist substance or fluid (electrolyte) might do,
and becomes polarized; the polarized, condition of
the muscle or nerve under these circumstances being
manifested, as the other points of the circuit, in the
longitudinal direction, one extremity being positive
or negative to the other; and when the electrodes
of a galvanometer are applied, one to each end, an
electric current is manifested. Nothing of this sort,
however, is manifested in the normal polarized
condition of the muscular or nerve fibre as it exists
in the animal body; the polar action, as then
manifested by the galvanometer, is in the transverse
direction, or, more correctly speaking, the tissue is
in one electric state negative, and the positive state is
external to it either in the sarcolemma or neurilemma,
or in the blood. Hence we see the important
difference between these two modes or conditions or
states. To. suppose, therefore, that an _ electric
current, in traversing a muscle or nerve, increases
its normal polarized condition, would only lead to
erroneous ideas of the subject; it may, however,
induce a change, under certain circumstances, in
the condition of the nerve, tantamount to an in-
creased action of the nerve or nerve force; but if.may
be very much doubted, without knowing what this
change is, whether we should be justified in calling.
it an increase of its natural polarized condition.

Since, then, the nerve fibre and the muscular
CHAP. Ix. MUSOULAR AND NERVOUS TISSUES. 103

fibre présent this peculiar polarized condition, we
may, without any hesitation, infer, that the two
forces, the muscular and nerve force, are both poLaR,
and, consequently, that muscular action and nerve
action are polar actions. With regard, however, to
the nerve, the mere circumstance of its electrical
state will not alone prove that nerve force is polar,
as we shall see in a subsequent chapter.

During life, the muscular and nerve fibre may be

- considered as existing in a state of tension’, a forced
state, and muscular relaxation may coincide, and
would be synonymous, with this polarized condition
or state of tension, and contraction, the result of a
depolarization of the muscular fibre. In the normal
state, this depolarization is induced by means of
nervous agency; but it may alsd occur from other
means, such as chemical or mechanical agencies,
or whatever is likely to produce disorganization.
Depolarization having occurred, 'the polarized state is
easily and readily restored by ‘the act ‘of: nutrition ;
hence contraction may be ‘partly considered as the
result of molecular attraction®. The particles con-

€ It would be of some importance to ascertain the state or
condition of the prisms in the electric organ of the fish, prior t to
their discharge of electricity. Theoretically, all the tissues ‘in
the animal body may be considered as being in an electric or
polarized state, presenting, howeyer, great differences in regard
to each other. io

8 I have already alluded to the opinion of Dr. Radcliffe, who
considers that muscular contraction is the result of molecular
attraction.
104 POLARIZED CONDITION OF THE CHAP. TX.

stituting the muscular fibre being in a state of self-
repulsion whilst in this polarized condition, would
resist the force of molecular attraction unless depo-
larized; and, according to this view, the results of
muscular contraction would necessarily follow in
conformity to the law as laid down by Scuwann.

The nerve fibre existing also in a state of tension,
whatever influences this state would also produce 2
depolarization of its fibre, the result being manifested
by muscular contraction, or pain. As it is only
during the period of this depolarization, when the
tension is altered, that contraction occurs, we have
some clue, as pointed out by Dr. Topp*, to the
reason why contraction only ensues at the opening or
closing of the circuit, and not during the continuance
of the passage of the current along the nerve. The
constant current does not induce those momentary
changes necessary for the production of muscular
contraction; it is only at the opening and closing of
the circuit that the tension of the fibre is affected.
The question, however, may be asked, How de we
account for the fact, that an inverse current through a
nerve will cause tetanic contractions, whereas a direct
current has no such effect? In this instance, the
inverse current may produce an altered condition of
the polarized state; but I do not believe, as has been
already stated, that it increases the normal polarized
condition; and if contraction be due to momentary

5 Cyclopedia of Anatomy and Physiology; Art. « Physiology
of the Nervous System.”
CHAP, IX. MUSCULAR AND NERVOUS TISSUES. 105

changes in the condition of the nerve, the tetanized
state of the muscle might be a necessary consequence
until the nerve had acquired its normal and per-
manent condition. But the same remarks might be
made of the nerve in which the direct current has
passed, and yet no contraction occurs. This is a
difficulty which at present we cannot satisfactorily
overcome; but the fact is of some importance, as
indicating a dependence upon the direction of the
electric current in its passage along the nerve, and
shewing that a peculiar state is induced in one case
and not in the otheri, My endeavours to ascertain
what this state may be by means of the galvanometer
have hitherto failed.

In all these discussions, the importance of con-
sidering the conditions both of the nerve tissue and
muscular tissue, in regard to their nutrition*, cannot

i Marreuccr believes that the excitability of the nerve is
inereased by the inverse current, and diminished by the direct
current. Phil. Trans. 1846, part iv. p. 488. It is possible that
the inverse current may keep up the normal electric condition of
the nerve, inasmuch as the current is similar in direction to the
natural current, and the direct current may destroy this normal
state, being in opposition to it. Under these circumstances, the
nerve current, if not increased by the inverse current, should
indicate some evidence of its continuing longer, and the opposite
effect should be produced by the direct current. At present my
experiments have failed to shew this.

k I cannot do better than refer to the article on the “ Phy-
siology of the Nervous System” in the Cyclopedia of Anatomy
and Physiology, by Dr. Todd, in which this fact is clearly
pointed out.
106 POLARIZED CONDITION OF THE OHAP. IX.,

be too strongly insisted upon. It is by nutrition
that the force is maintained, and it is by this act
that it is renewed. If the changes in each tissue
are not properly carried on, or should fail in one or
both of them, spasms or convulsions may be induced
at one time, or the contrary effect, such as paralysis,
might occur at another.

It may be urged as an argument against the
views now taken, of muscular force and nerve force
being polar, that they are considered as identical.
So far as they are potar they are identical; but the
conditions under which the force exists in the two
tissues differ. In the muscle it is limited to, and
associated with, that tissue, and may be considered
as existing in a static form. In the nerve it may
also exist in this form, the static, but it is capable
also of being transmitted from one point to the other,
in consequence of the peculiar organization of the
nervous tissue. The identity between the two forces
removes those difficulties that might otherwise arise
in considering their reaction one upon the other.
Muscular force and nerve force must not be supposed
to be produced by their respective tissues, but asgo-
ciated with them; the modes under which they are
manifested differ, and would indicate that the form.
under which nerve force exists would prove it to be of
a higher character than that of muscular force}.

1 Vide Fanapay’s Paper on the Gymnotus, (Experimental
Researches, vol. ii. p. 16.) on the “ Relation between Nervous
Power and Electricity.”
CHAP, IX. MUSCULAR AND NERVOUS TISSUES. 107

It may be urged, if nerve force be a polar force,
-how is it possible to conceive that mental acts, that
phenomena connected with the mind, should be the
result or the manifestation of polar action? Without
entering into the discussion as to how far mental
acts are the result of an action of the brain, or
whether it be through the medium of the brain that
the mind acts upon the body, or whether mental
phenomena are polar phenomena, I nevertheless
believe, that the phenomena associated and con-
nected with nervous action are confined to, and can
only become manifested in, the animal kingdom;
and although they may bear a close relation or
connection with the action of other polar forces, they
will nevertheless form a distinct class, a class sui
generis, and perhaps the highest form by which polar
phenomena can become manifested.
CHAP: X.

ON THE MANIFESTATION OF ELECTRIC FORCE, OF
CHEMICAL FORCE, AND OF HEAT, DURING MUSCULAR
CONTRACTION.

Sect. I. On the Manifestation of Electric Force during
Muscular Contraction.

I shall purposely abstain from entering upon the
personal disputes that have arisen during the dis-
cussion of some of the questions that will now
occupy our attention, and only refer in a general
note to the principal sources from whence I have
been enabled to obtain such views as are confirmed
by experimental evidence, and which are now
entertained upon the subject of our present inquiry?.

» Annales de Chimie et de Physique, 3¢ série, vol. xv. p. 64;
vol. xxx. pp. 119, 179; vol. xxxix. p.114. Comptes Rendus,
vol. xxviii. pp. 570, 641, 658, 668, 782; vol. xxx. pp. 349, 406,
479, 512, 563, 699; vol. xxxi. pp. 28, 91, 818; vol. xxxii. p. 131.
Bibliothéque Universelle de Genéve, Fev. 1850, Juin 1858.
On Animal Electricity; being an Abstract of the Discoveries of
Emil du Bois-Reymond, &c. edited by H. Bence Jones, M.D.
F.R.S. London: Churchill, 1852, 8vo. Lettre de Charles Mat-
teucci 4 M. H. Bence Jones, F.R.S. Florence: Imprimerie Le
Monnier, 1853, 8vo. On Signor Carlo Matteucci’s Letter to
H. Bence Jones, M.D., F.R.S. &c. By Emil du Bois-Reymond.
London: Churchill, 1858, 8vo. As the original Paper was read
before the Royal Society in 1855, my readers will find some
further observations of Marreuccr in regard to the subject in
CHAP. xX, §.1. ELECTRIC FORCE, &c. 109

The fact long since obtained by Marrevoct, viz.
that of causing the muscles of a galvanoscopic frog
to contract by placing its nerve upon the muscles of
another animal during their contraction, is well
known; and in a communication® to the Royal
Society, Martrucc: has adduced strong reasons for
believing that an electric disequilibrium is produced
during muscular contraction.

Du Bois Revmonp* has also satisfactorily shewn,
that when the hands are placed in two separate
vessels containing water, and connected with a galva-
nometer, that then, upon making the muscles of one
arm contract, an effect is produced upon the needle.
These results have been confirmed by ZantEDESCHI‘.
Borr®’, and Tynpauu‘,

The results obtained by Drespretz*, BecquERE.},
and Marrevccri, have thrown strong doubts upon
the conclusions deduced by Dv Bors Reymonp.
Several experiments undertaken by myself, both
prior and subsequent to the knowledge of Du Bors
Reymonp’s researches, tended to confirm in my

the Bibliothéque Universelle de Genéve, in the Annales de
Chimie et de Physique, and in the Comptes Rendus for the
year 1856.

> Philosophical Transactions, 1850. Ninth Series.

© Comptes Rendus, vol. xxviii. p. 64].

4 Bibliotheque Universelle de Genéve, Fev. 1850.

e Thid.

* British and Foreign Medical Review for Jan. 1854, p. 14].

& Comptes Rendus, vol. xxviii. p. 6538.

h Tbid. p. 668,

i Thid. p. 782.
110 ELECTRIC FORCE cHaP. x. §.1.

opinion the doubts expressed by these inquirers.
But the positive evidence adduced by Dv Bois
Reyrmonp by means of his delicate galvanometer,
combined with that of Marreuccr obtained by means
of the frog, only made it incumbent upon the
opponents of Du Bors Reymoxp to disprove his
conclusions, if capable of disproof, more by stronger
experimental evidence than by theoretical arguments;
hence the renewal of the present inquiry.

In relating the experiments, to avoid unnecessary
prolixity, I shall endeavour to be as concise as pos-
sible, although it may be considered that the various
sources of error have not been sufficiently eliminated.
My great point, however, will be to establish facts ;
and whatever observations it may be necessary to
make in reference to the origin of the effect pro-
duced, these will form the subject of the concluding
remarks, and I shall just relate in a general
manner some results that were first obtained by
means of a galvanometer consisting of but few coils.
To two brass handles of an ordinary medical electro-
magnetic machine, were attached thick copper wires,
each about 8 inches in length, and bent. Similar
copper wires were connected with the galvanometer,
their free ends communicating with mercurial cups,
these cups forming the means of connexion with the
brass handles. Holding the metallic handles firmly,
grasping one of them and contracting the muscles
of the arm powerfully, and doing this alternately
with each arm, I at first failed to obtain any, or if
CHAP. X. §. Ie DURING MUSCULAR CONTRACTION. Lil

any, but indecisive results. Upon repeating the
experiments on another occasion, some definite
result was ultimately obtained, and also a clue to
my former failures. I found that when the muscles
of the arms were contracted alternately at definite
periods, and continuing this act for some time, that
as the hands became moist, a decided effect upon the
needle occurred, indicating the contracting arm to
be positives to the other. These results may be
considered as due partly to the reaction of the acid
secretions of the hand upon the metallic electrodes,
partly to the skin becoming a better conductor than
the dry cuticle, and partly perhaps to thermo-electric
action.

The question now arose, could not the effect
which might be due to muscular contraction coincide
with that which arose from the action of the cutaneous
secretions? From the results obtained by Du Bots

k Some difficulty is frequently experienced in comprehending
the results obtained by different inquirers in reference to the
direction of the current; it is uncertain to which of the circles
of ‘the old construction, the simple or compound, reference is
made for illustration, or whether it be the positive metal or the
positive electrode that is referred to; hence arises an apparent
contradictio, The direction of the current is of the utmost
importance to be attended to in accounting for the effects
produced. I always allude to the simple elementary circle for
illustration; if zinc, platinum, and dilute acid, be formed into a
circuit, the current goes, according to the usual mode of
expression, from the zinc fo the platinum; the platinum being
the positive electrode. In the combination of an acid with an

alkali, the electrode in contact with the acid is the positive
electrode.
112 ELECTRIC FORCE CHAP. X. §. 1.

Reymonp’, it would appear, that the direction of the
current due to muscular contraction is inverse, i.e.
from the hand to the shoulder.

Several other experiments were undertaken, in
which different solutions were employed to moisten
the hands; the effect upon the needle was now
much greater. When one hand was moistened with
a weak alkaline solution and the other with water,
upon contracting the muscles of the arm holding
the alkaline electrode, this became negative to the
other; but by proper management, by not having
the solution too strong, this arm could be made to
become positive, the current occurring during mus-
cular contraction overcoming the influence of the
alkaline solution. Feeling the force of the objections
that might be raised in reference to the use of the
metallic electrodes, I do not think it necessary to
relate any other experiments in which these instru-

“ments were used.

A galvanometer™ of the following construction
was now employed. It consisted of two coils, placed
one above the other so as to produce the full effect
upon both needles, with an index to indicate the
amount of deflection. Each coil was 2ginches in
length, and the same in breadth, consisting of 1500

' Rapport sur les Mémoires rélatifs aux phénoménes électro-
physiologiques présentés 4 l'Académie par M. E. du Bous-
Reymonp, Comptes Rendus, vol. xxxi. p. 28.

= Vide Farapay’s mode of employing a galvancmeter. Phil.
Trans. Series xxviii. 1852.
CHAP. X. §. I. DURING MUSCULAR CONTRACTION. 113

turns; the thickness of the wire 37 gauge. The
needles were rather less than 2 inches in length;
the index, of ivory, 8 inches in length. As my
object was to ascertain, if possible, the eaistence of
the force rather than the amount, a further de-
scription of its delicacy will not be necessary.

Two copper clamps were made, each 4 inches in
length, tapering at one extremity so as to be con-
nected with the binding-screws of the galvanometer,
the other extremity being bent down at right angles
to the extent of half an inch, presenting a surface
1} inch in breadth, and to which was also attached a
piece of copper by means of two screws; by these
the platinum electrodes were securely fastened, and
those that were generally used consisted of platinum
foil, each 24 inches in length and 1 inch in breadth.

The vessels usually employed to hold the solutions
were two cupping-glasses, each 22 inches in diameter,
2% inches in depth, and contained rather more than
four ounces of fluid. The glasses being half filled
with a weak solution of common salt, covering the
electrodes to the extent of an inch, two and some-
times three fingers of each hand were held perpen-
dicularly in the vessels, the middle finger resting
upon the bottom of the glass vessel. When first
introduced, a slight tremulous motion of the needle
was observed; upon taking the fingers out of one
vessel and reintroducing them, and repeating this
act, a slight effect appeared, at first definite, but this
soon subsided. Similar effects were observed when

I
114 ELECTRIC FORCE CHAP, xX. §.1.

the fingers of the other hand were used in a similar
manner. The fingers last introduced were not
always positive or negative to the others. Keeping
the fingers in, then moving one of the fingers so as
to make the fluid rise and fall upon the surface of
the electrode in the vessel, produced but little
motion of the needle. After the fingers had been in
for some time, and the needle had become quite
stationary, upon contracting the muscles of one arm
an effect occurred upon the needle indicating the
contracted arm to be positive to the other 3°; by
contracting the muscles of each arm alternately, the
effect amounted to 5°. The result was definite, and
the motion of the needle steady.

Dv Bors Reymonp® considers that there are five
circumstances as influential in producing a current:
viz. lst, température inégale; 2nd, durée inégale de
Vhumectation avec le liquide conducteur; 3rd, tension
inégale de la peau; 4th, lésion de l'une des places de
la peau; 5th, transpiration inégale. I could not
refer the effects that were obtained to either of these
circumstances; to the tension of the skin, for
instance.

Three solutions were now prepared; the first
consisting of a concentrated solution of common
salt; the second of sulphuric acid, one part of strong
acid to six parts of water; and the third of one part
of liq. potassss (Pharm. Lond.) to four parts of
water,

. Bibliotheque Universelle de Genave, Juin 1853.
CHAP. X. §. I. DURING MUSCULAR CONTRACTION, 115

It was found necessary that the following pre-
cautions should be strictly attended to. The solutions
should be prepared and well mixed previous to their
use, and the electrodes covered to the same extent.
The hands and fingers should be thoroughly clean ;
to attain this object, they were first washed with the
ordinary curd or Windsor soap, and afterwards well
rinsed in common water, and wiped comparatively
dry with a clean towel. The same towels should
not be employed when using the different solutions,
and it was found better to work on different days
with each solution; for the liquids soaking in
between the nails and the fingers became a source
of some difficulty to remove, and a cause of some
embarrassment in judging of the final result.

It need hardly be stated, that the surfaces of the
electrodes should be clean and the contacts perfect.

With the solution of common salt. Upon the first
introduction of the fingers, a slight tremulous motion
of the needle occurred. Withdrawing the right-hand
fingers and reintroducing them immediately after-
wards, and repeating this act a few times, a slight
positive effect was produced upon the introduction of
the fingers. Withdrawing the left-hand fingers in
the same manner, a slight negative effect was at first
obtained, but after a short time the effect became
indefinite, and ultimately slightly positive. Keeping
the fingers in and contracting the muscles of the
arm, the fingers of the contracted arm were positive
4° to 5°, and made to increase.
116 ELECTRIC FORCE CHAP. X. §.1.

The solution in one vessel was now diluted to
one-half. Upon the first introduction of the fingers,
the strong solution was positive 5°. Keeping the
fingers in and waiting until the needle had become
motionless, the contracted arm was positive to the
other; if the arm connected with the strong solution
was contracted, the effect was greater than when the
other was contracted, the current in the former case
rising to 5°, in the latter to 2° or 3°.

With the acid solution. Upon the first introduction
of the fingers, the needle would sometimes go 30°
or 40°, but generally speaking it would oscillate first
to one side and then to the other. Withdrawing the
fingers of one hand and then reintroducing them,
this hand was positive to the other. Keeping the
fingers quiescent, and contracting the muscles of the
arm, the corresponding fingers were positive 4°.

The solution in one vessel was diluted to half the
strength of the former; the strong solution was
positive to the otber upon the introduction of the
fingers. If the difference between the two solutions
was not too great, (the exact strength being difficult
to state,) I could determine a slight current to pass
in a constant direction, and then make the current
arising during muscular contraction overcome this
constant current. Strong solutions were found best
for this purpose, from their forming, perhaps, a
better conducting liquid than the weaker solutions.

With the alkaline solution. Upon the first intro-
duction of the fingers no definite result, the needle
CHAP. X. §. 1. DURING MUSCULAR CONTRACTION. 117

tremulous. Withdrawing the fingers and reintroducing
them, the effects varied, but, generally speaking, the
reintroduction of the fingers produced a neyative
result. The effect due from muscular contraction
was definite from 2° to 4°, the fingers of the con-
tracted arm being positive.

The solution in one vessel was diluted to half the
strength of the other. Upon the introduction of the
fingers, the diluted solution was wpositive to the
stronger. I was enabled in this instance, as with
the acid solution, to obtain a solution of such
strength as to give a constant current in a certain
direction, and then make the current due from
muscular contraction overpower this current. As
this fact is one of some importance, it will be
necessary to state the mode of ascertaining this
constant current. If we find, either upon the
introduction of the fingers of both hands at the same
time, or upon the introduction of the fingers of one
hand, that a current existed in one direction to the
amount of about 2°, the current occurring during
muscular contraction, if it coincided with this con-
stant current, would cause the needle to advance to
4° or 5° or more; but if it has to overcome this con-
stant current, the needle would only move 2° or 8°.
I need scarcely add, that the needle of the galva-
nometer should continue to indicate this current
whilst the fingers remain in the solution, which may
be indicated by the needle receding to its normal
position upon the withdrawal of the fingers. A
118 ELECTRIC FORCE cHaP. x. §.1.

great difficulty, however, is frequently experienced in
obtaining this constant current.

Several other experiments might be related in
which the electrodes were made to differ in size, one
being narrow, the other broad; or where one was
made to dip deeper into the solution than the other.
The general results indicated that a difference in
extent between the surfaces of the platinum electrodes
and the solutions, occasioned an effect upon the
needle upon the first introduction of the fingers.
In other experiments larger vessels were employed,
so as to insert the whole of the hand and wrist;
the results coincided with those that have been
related, the effect however was greater.

The solutions were made to vary as to temperature
by placing the glass in a vessel containing hot
water, and then carefully stirring the solution so as
to make it completely uniform. One vessel was at
the temperature 65° F. and the other 115°. The
results upon the first introduction of the fingers
were indecisive. The hot solution was not always
positive to the cold solution. The effect during
muscular contraction could always be obtained.

I agree with Du Bois Reymonp as to the import-
ance of attending to the five circumstances to which
he refers, and which have been already alluded to.
The circumstances that appear to me to be the most
influential in masking the ultimate result are,
Ist, the action of the fluid upon the surface of the
electrodes; and, 2ndly, the reaction of the cutaneous
CHAP. X. §.1. DURING MUSCULAR CONTRACTION, 119

secretions upon the fluids. Although we cannot
remove these sources of error, we have it nevertheless
in our power to counteract their effects, by shewing
that the current consequent upon muscular con-
traction can be made to overcome that arising from
either of the two former actions.

I have not yet alluded to the difference which
appears to exist between the results obtained by
Du Bors Reymonp and myself, viz. the direction of
the current, Dv Bors Reymonp’s experiments indi-
cate that the current is inverse, i.e. from the hand to
the shoulder during muscular contraction; my re-
sults, on the other hand, point out that the current
is direct, i.e. from the shoulder to the hand. I do
not think that my results differ much from those of
Du Bors Ruymonp; but as the discussion of this
question will involve certain theoretical views, what-
ever observations I may have to make will be deferred
to the concluding remarks °.

° My original Paper was read before the Royal Society, since
then I have had the opportunity of attending the interesting
lectures of Du Bors Rermonp at the Royal Institution. Du Bots
Reymonp considers, as far as I could understand, that when the
whole of the hands are immersed in the solution, and the
muscles of the arm are made to contract, then the current is
due to the swollen state of the skin, and perhaps to other cir-
cumstances; but should we be justified, I would ask, in con-
cluding, that when the fingers alone are in the vessel, that then
the effect is due to their swollen state? If Du Bors Reymonp
maintains that the current due to muscular contraction is
inverse, i.e. from the hand to the shoulder, I can only add that
I have never been able to obtain that constant effect. It cannot
120 ELECTRIC FORCE cHap. x. §.1.

With the assistance of three friends, an attempt
was made to increase the effect upon the needle by
forming a pile, as it were; we could obtain the
effect, but there was no decided increase.

Several experiments were undertaken with the
rheoscopic frog? in lieu of the galvanometer; the
results were not so satisfactory as could be desired,
to justify their being recorded.

 

The posterior limbs of a frog, separated at the
pelvis, but connected by means of the lumbar nerves
and a portion of the vertebral column, were each
placed in separate vessels containing the solution of
common salt; the muscles of one limb were then
made to contract, and an immediate effect upon the

be denied that it frequently happens, upon the first repetition
of the experiment, that the current may appear in favour of this
opinion. Dzsprerz has remarked, that the current may appear
first in one direction and then in another. I cannot insist too
strongly upon the necessity of having the hands perfectly clean,
and I am convinced that the failures and contradictory results
which arise are due more to the want of attention on this point
than to any thing else. The direction of the current is a fact
of the utmost importance, as we shall hereafter see.

P The term rheoscopic has been recommended in the Report
of the Committee of the Academy of Paris, in preference to that
of galvanoscopic. I have employed both terms. When it is
used for the detection of the current, the former term is most
applicable; but the frog may be a test of a force in which the
current force, in accordance with our present notions of force,
cannot be shewn to exist. If the dynamic condition and the
current condition of force be considered as equivalent terms,
then rheoscopic would be unobjectionable.
CHAP. X. §.1. DURING MUSCULAR CONTRACTION. 121

needle was observed, the contracted limb being
positive to the other from 8° to 4°. To prevent the
fluid from being scattered upon the electrode, a piece
of glass was attached to the part as a weight to avoid
too great motion of the limb. In some instances
both feet were removed: the effect upon the needle
was still the same.

Similar results were obtained with the acid solu-
tion, but with the alkaline solution the effects varied,
especially so if the solution were strong. The
alkali acted apparently upon the mucous secretion
of the skin.

Great care was required to have the cutaneous
surfaces clean previous to the introduction of the
limbs into the solutions, so that no current could
arise therefrom.

Is it necessary to place the nerve of a galvanoscopic
frog in contact with the longitudinal and transverse
section of a muscle in order to obtain the necessary
contractions? Repeating the experiment of Mar-
rEuccI4, it was found that the contraction might be
obtained without placing the nerve in contact with
the muscle. At the same time I must add, that the
effect upon the galvanoscopic frog appeared greater
when its nerve was placed transverse to the muscular
fibres than in any other position.

 

@ Phil. Trans. 1850. Ninth Series. Annales de Chimie et de
Physique, Juin, 1856.
122 ELECTRIC FORCE CHAP. X. §.1.

The results of these experiments tend to establish
the following conclusions, viz.

First. That during muscular contraction in man
and in frogs, an effect upon the galvanometer may
be obtained indicating the manifestation of an electric
current.

Secondly. That this manifestation of an electric
current is due, in a great measure, to secondary
reactions, viz. between the animal secretions and the
solutions on the one hand, and between the solutions
and the platinum electrodes on the other; but that
there nevertheless: remains a residual effect which
cannot be referred to either of these actions, or to
those pointed out by Du Bors Reymonp.

Concluding Remarks.

The numerous instances in which an electric
current may be shewn to exist, naturally renders
any conclusion deduced from results obtained by
means of the galvanometer extremely doubtful. If
these remarks are applicable to physical researches,
where we have such control over our experiments as
to afford us facilities favourable for eliminating
sources of error, how easily may we conceive that
they would apply with far greater force to phy-
siological researches devoid of such facilities. The
strong prejudices which exist in reference to electro-
physiological inquiries cannot therefore be a matter
of much surprise, but must create a great difficulty
to any individual who shall attempt the elucidation
CHAP. X. §.1. DURING MUSCULAR CONTRACTION. 123

of any electro-physiological problem experimentally ;
for not only has he to satisfy, from the mixed cha-
racter of the inquiry, the extreme views of the
physicist on the one hand, and those of the phy-
siologist on the other, but they also afford the
indolent inquirer a ready means of apparent refu-
tation, and a powerful weapon to the controversialist.
That these opinions are not ill-founded might be
easily shewnt. Feeling the importance of basing
the conclusions in these inquiries upon strictly
experimental evidence, in discussing the different
views that may be entertained in regard to the
evidence upon which the experiments justify us in
concluding that some force is evolved during mus-
cular contraction, I shall confine my observations to
the experimental results obtained by Marreuccr and
Dv Bois Rermonp, and endeavour to avoid every
thing of a purely controversial character.

Martevcei* has proved, and shewn by means of
the galvanoscopic frog, that during muscular con-
traction the muscles of the galvanoscopic frog may
be excited to contract, and that for this purpose it is

t Strange to say, it has been urged, that the time has not yet
arrived for the prosecution of these experiments. This is the
only tangible objection that the author has yet had an oppor-
tunity of refuting. That objections may be started he is per-
fectly convinced; but as the inquiry professes to be experimental,
the objections must be supported by experimental evidence
before he can notice them.

* Phil. Trans. 1850. Ninth Series. Annales de Chimie et de
Physique, Juin, 1856.
124 ELECTRIC FORCE oHAP. x. §.1.

not necessary that the nerve should be brought into
contact with different portions of the muscular fibre.
In repeating these experiments, I have been able to
confirm the results obtained by Marreuccr.
Marrezucort, in his endeavours to ascertain whether
the muscular current was increased during muscular
contraction by forming piles with muscular elements,
failed to obtain any decisive result. Du Bois Rey-
monp, by means of his galvanometer, has satisfactorily
shewn, that when the electrodes are so arranged with
a muscular element that the current (muscular) passes
through the instrument, that then, upon the con-
traction of the muscle, the needle of the instrument
recedes, and this he calls “ the negative variation”
of the muscular current. This fact, established by
Dv Bors Reymonp, and also the results obtained by
Marrgvuccir, have been confirmed by some of my
own experiments. But I cannot help thinking with
Marrecccr®, that the falling or the receding of the
needle in Dv Bois Reymonp’s experiment may be
attributed in a great measure to the variation in the
contacts between the surfaces of the muscle and the
electrodes during the act of contraction. I am not
aware that the existence of the muscular current is
disputed by any one; and with respect to its origin,
there can be no doubt that it arises from nutrition,
and may be manifested under two points of view,
as I have endeavoured to shew in chapters vi. and viii.

t Phil. Trans, 1845.
~ Phil. Trans. 1850. Ninth Series.
cHaP. X. §.1. DURING MUSCULAR CONTRACTION. 125

We have then now two distinct questions for our
consideration: 1st, Is there, or is there not, any force
evolved during muscular contraction? and, 2ndly, Is
the muscular current affected during muscular con-
traction? And this brings me to speak of the results
we have been considering in the present chapter.
Du Bois Reymonn’s results lead him to consider,
that in the frog the current is direct, and in man
inverse, a3 shewn by the galvanometer. My experi-
ments lead me to believe, that the current is direct in
both instances. Upon carefully looking over a Paper
by Du Bois Reymonp* upon this question, it appears
to me that he frequently obtains the direct current;
but laying so much stress, as he does, upon the
necessity of a current (muscular) circulating through
the instrument prior to contraction before he can
conclude that the resulting action upon the needle
is what he calls “the negative oscillation” of the
muscular current, that his object was to ascertain
whether the muscular current in the human subject
was not affected during muscular contraction, as in
the frog, when arranged with a muscular element in
the manner I have stated in the preceding paragraph.
But then the question will arise, how can we account
for the effects, when the limbs of a frog are placed in
separate vessels, as is done with the hands? I may
be mistaken in my opinion. As I have not been
able to obtain this inverse current, and if Du Bois
ReyuonpD has been endeavouring to obtain this inverse
» Bibliothéque Universelle de Geneve, Juin 1853.
126 ELECTRIC FORCE CHAP. x. §. 1.

current to prove “the negative variation” of the
muscular current in the human subject, then the
object that each of us has had in view differs: mine
has been to ascertain whether any force is evolved
during muscular contraction; Dv Bors Reymonp’s,
whether the muscular current is affected during
muscular contraction. The importance of Dv Bors
Rrymonp’s researches cannot be denied; but it
appears to be, and is, of extreme importance that
the two questions should be kept perfectly distinet,
although perhaps intimately connected with each
other.

The results of my inquiries lead me to believe,
that during muscular contraction a force is evolved,
as in the fish, but that it is only during extraordinary
muscular exertion that it can become manifest to the
galvanometer. I am perfectly aware of the objections
that may be urged in reference to the fish being
provided with a special apparatus; and in my first
endeavours to obtain some result with the galva-
nometer, in which I failed to obtain any evidence of
the existence of a force being evolved, I was then
led to the conclusion as to the improbability of any
force becoming free, as it were, during muscular
contraction; that whatever force might be evolved
would be expended or converted during that act;
but I could never get over the-difficulty which the
results of Marreucct, obtained by means of the frog,
presented for consideration, and which is doubly
increased by the results that have now been related
see ees

CHAP. X. §. 11. DURING MUSCULAR CONTRACTION. 127

in the present chapter. -In reference to the fish,
also, it must be remembered, that the force evolved
bears some relation, according to Marreucoty, “ to
the activity of the functions of circulation and of
respiration, and of every act of nutrition.” The
apparatus may be a means for the evolution of the
force, but not a producer of the force; and there are
some reasons for believing that the electric condition
of the blood in the living animal must not be over-
looked.

The question in what way the nerves influence
muscular contraction, and have in the develope-
ment of the force during muscular contraction, or
in the evolution of the force in the fish, I am not
now discussing. It is of primary importance to
ascertain first of all what does take place. The in-
fluence that the nervous system has over these
results is a subject for future consideration.

Sror. II. On the Manifestation of Chemical Action

during Muscular Contraction.

That chemical changes take place in muscles
during muscular action, has been inferred from the
changes produced in the muscular tissue after
violent exercise. Marrrucci?, however, has shewn,
that during muscular contraction oxygen is absorbed,
and that carbonic acid and nitrogen are evolved.
The mode of conducting the experiment is as follows:

y Phil. Trans. 1847, p. 241.
z Philosophical Magazine, June, 1856.
128 CHEMICAL FORCE cHaP. x. §. IL

“ Take,” he says, “ two wide-mouthed glass phials of
equal size, 100 or 120 cub. centims.; pour 10 cub.
centims. of lime-water (eau de chaux) into each of
these phials. Prepare ten frogs in the manner of
Gatvant; that is, reducing them to a piece of spinal
marrow, thighs and legs without the paws, which
are cut in order to avoid contact with the liquid in
the phials. The cork of one of these phials is
provided with five hooks, either of copper or iron,
on which five of the prepared frogs are fixed.
Through the cork of the other phial are passed two
iron wires, bent horizontally in the interior of the
phial; the other five frogs are fixed by the spinal
marrow to these wires. This preparation must be
accomplished as rapidly as possible, and both the
phials be ready at the same instant, and great care
taken to avoid the contact of the frogs with the sides
of the phials or the liquid. When all is in readiness,
with a pile of two or three elements of Grove, and
with an electro-magnetic machine such as is em-
ployed for medical purposes, the five frogs suspended
on the two iron wires are made to contract. After
the lapse of five or six minutes, during which time
the passage of the current has been interrupted at
intervals in order to keep up the force of the con-
tractions, agitate gently the liquid, withdraw the
frogs, close rapidly the phials, and agitate the liquid
again. You will then see that the lime-water con-
tained in the phial in which the frogs were contracted
is much whiter and more turbid than the same liquid
CHAP. X. §, I. DURING MUSCULAR CONTRACTION. 129

contained in the other phial in which the frogs were
left in repose. It is almost superfluous to add, that
I made the complete analysis of the air in contact
with the frogs according to the methods generally
employed.” He calls the phenomenon, ‘ muscular
respiration, and states, that “‘a muscle which con-
tracts, absorbs, while in contraction, a much greater
quantity of oxygen, and exhales a much greater
quantity of carbonic acid and azote, than does the
same muscle in a state of repose. A part of the
carbonic acid exhales in the air, the muscle imbibes
the other part, which puts a stop to successive
respiration, and produces asphyay of the muscle.
Thus a muscle even ceases to contract under the
influence of an electro-magnetic machine enclosed
in a small space of air: this cessation takes place
after a longer interval of time if the muscle is in the
open air, and much more slowly still if there be a
solution of potash at the bottom of the recipient in
which the muscle is suspended. Muscles which have
been kept long in vacuum or in hydrogen are never-
theless capable, though in a less degree, of exhaling
carbonic acid while in contraction; this proves clearly,
that the oxygen which furnishes the carbonic acid
exists in the muscle in a state of combination.”

That different gases present great differences in
their influence upon the irritability of the muscular
tissue, and consequently over contraction, has been
long known.
130 HEAT CHAP. X. §. III.

Sror. III. On the Manifestation of Heat during
Muscular Contraction.

Brcqueret and BrescHer*, in their ingenious
experiments upon the relative temperature of the
different tissues in the living animal, also found
that, during muscular contraction, the temperature
of the muscular tissue was increased. The amount of
deflection was equivalent to about 1° of Fahrenheit.

Marrevccr® took two flasks, in each of which he
suspended the limbs of five frogs, and in the middle
of these limbs a delicate thermometer. Having waited
until the temperature of the limbs had become
stationary, he then caused the muscles in one of the
flasks to contract violently. In the first experiment,
the temperature of the air was -+- 12°60, the ther-
mometer in the middle of the frogs indicated +- 13°10;
upon making the muscles contract for five or six
minutes, the latter indicated + 13°50. At this point
it continued stationary during eight or ten minutes.
In another experiment, the temperature of the air
was -+ 12°80, in the middle of the frogs + 13°50,
during the contractions it ascended to + 18°95.
An hour afterwards, the temperature being lowered
to -+ 13°40, he then excited the muscles to contract,
which they did although feebly, and the temperature
only indicated +- 18°60. In a third experiment, the
temperature of the air being + 12°70, in the middle

® Becquerel, tom. iv. p. 21.
> Annales de Chimie et de Physique, Juin, 1856.
CHAP. X. §. 111. DURING MUSCULAR CONTRACTION. 131

of the frogs + 18°55; after five minutes of con-
traction the temperature was increased to -++ 14°.
A current was passed fourteen hours after the experi-
ment, but neither contractions nor any increase of
temperature were observed.

The results arrived at in the present chapter will
lead to the following conclusions.

‘First, That during Muscular Contraction, Electricity
is evolved.

Secondly, That during Muscular Contraction, Chemi-
cal Action takes place.

And, thirdly, That during Muscular Contraction,
Heat is evolved.

Marrevccr says, “Je pense qu’on doit désormais
admettre, comme prouvé par ]’expérience, que l’action
chimique de.la respiration musculaire pendant la
contraction est la cause de la force qui se développe
dans les muscles.”

Now it does not appear to me that we would be
justified in considering one of these circumstances
either as a cause or as an effect of the other; that
the chemical action, for instance, should be the cause
of the electricity, or vice versd. The muscular fibre
during life possesses an electric state, exists in
a state of tension, and during contraction this state
is lowered, and the force becomes free. This state
of tension is again restored by nutrition. Chemical
action takes place and heat is evolved at the same
time, and together with the evolution of the electric
132 HEAT DURING MUSCULAR CONTRACTION. CHAP. X. §. ITI.

force during muscular contraction. It would be a
very interesting question to ascertain whether these
three effects, the developement of electricity, of che-
mical action, and of heat during muscular con-
traction, took place according to any definite ratio.
It would also, as observed by Marrevccr, be ex-
tremely important, “‘des’assurer si l’activité de ’organe
électrique de la torpille qui ne donne lieu qu’a une
décharge électrique, sans chaleur et sans travail
mécanique (contraction), est accompagnée ou non
d'un phéenoméne analogue 4 la respiration musculaire.
Lrexpérience est difficile mais important.”
CHAP. XI.

ON NERVE FORCE. NOT CURRENT FORCE SHEWN BY
THE GALVANOMETER 5; THE GALVANOSCOPIC FROG,
AND THE MAGNETIC NEEDLE. A POLAR FORCE.

Is nerve force a polar force? If so, in what
respects does it differ from other polar forces? or
what evidence have we that it is a polar force at all?
These are questions which no doubt arise in the
minds of many physiologists of the present day.
Without entering into any detailed account of the
various opinions that are entertained in regard to
the nature of nerve force, it may be fairly considered,
that those who entertain the opinion that nerve
force is a polar force, are called upon, in the present
state of the question, to give some direct experi-
mental evidence in support of their conclusion: the
onus probandi evidently rests upon their shoulders.
We cannot remain satisfied with the vague notions
that animal life and electricity are identical, or that
nerve force and electric force are identical, or that
nerve force differs entirely from electric force, or
that vital forces are totally distinct from inorganic
forces. The mind will not and cannot rest satisfied
with these vague assertions; it requires something
more definite. We want to know, if possible, how
far they agree, and in what respects they differ.
To answer these questions satisfactorily, it will
134 NERVE FORCE. CHAP. XI.

be seen, that some of the most difficult physiological
ptoblems are now presented for our consideration ;
and although we might not be enabled to succeed in
solving them to the extent we could wish, it is to be
hoped that the attempt will be neither useless nor
unprofitable.

The first question that will arise is the following:
Can we detect any manifestation of CURRENT FORCE in
nerves DURING nerve action ?

It will be necessary to make a few preliminary
observations respecting the employment of the terms
nerve action and nerve current.

The fact that current force exists in a nerve is
well known, and may be shewn, as was first pointed
out by Du Bors Reymonp, by placing the electrodes
of a galvanometer, one in contact with the tranverse
section of the nerve, and the other in contact with
the longitudinal section or side of the nerve: this
has been designated as the nerve current. So far
this nerve current does not differ from that which has
been called the muscular current, and which may be
obtained in the muscle in the same manner. I have
been led to consider, that this so-called nerve current
is dependent upon nutrition. It does not afford direat
evidence that the force which exists in the nerve as
nerve force, and which may be supposed to be trans-
mitted from one part of the system to another along
the nerve, is current foree: it only proves that the nerve
tissue, like the muscular tissue, is in an electric
condition—a condition no doubt necessary and
CHAP. XI. NERVE FORCE. 135

essential for nerve action as well as for muscular
action. Current force is not manifested when the
electrodes are placed at the extremities of a nerve,
the nerve being in a quiescent state; and this fact
does not prove that the force transmitted by the
nerve during nerve action is not current force. The
real question therefore is, whether during nerve
action, during the passage of nerve force along a
nerve, current force is manifested or not. We must
take care, however, and bear in mind, that the term
nerve current may be employed to express two distinct
ideas: 1st, The electric current manifested in the
nerve, and which indicates the electric condition of
tissue; and, 2nd, The force—nerve force—which is
transmitted along a nerve during nerve action.

VavassEuR* and Brranp1? and Davip" appear to
have obtained some results in their experiments
when the electrodes of a galvanometer were inserted
into different parts of a nerve. These experiments,
however, were undertaken prior to the knowledge of
the existence of the nerve current, and the effects
then observed may have been due to the electrodes
having been placed on different parts of a nerve, the
result being the so-called nerve current of Dv Bois
Reymonv.

The experiments of Pacinorrr and Puccrnorti,
repeated and confirmed by Marreucci, must not be
passed over. These inquirers inserted one electrode

a Murier’s Elements of Physiology; translated by Baly.
Second Edition, vol. i. p. 685.
136 NERVE FORCE. CHAP, XI.

into the brain, and the other into the muscles, when
a deviation of the needle to a large amount occurred,
the electrode in contact with the muscle being
positive to the other. In this instance, it might be
supposed that the current travelled from the brain
along the nerve to the muscle. I have alluded to
these experiments in chap. vi.; and as similar effects
upon the needle were obtained when the electrode
was inserted into the internal jugular vein instead
of the muscle, I have been led to suppose that the
effects are due to the electric condition of the
nervous tissue, the result of nutrition, and not as
indicating the passage of an electric current along
the nerve.

Prevost® and Dumas®, Person», MuLier®, and
Marrevcctr*®, have failed to obtain any evidence of
current force being manifested when the electrodes
of the galvanometer were inserted in the nerves of a
living animal. Some of my earliest experiments
were undertaken for the purpose of ascertaining this
point; and although results were occasionally ob-
tained, nevertheless, as the experiments were per-
formed prior to the knowledge of the existence of
the electric condition of the nervous tissue, I have
no doubt that the effects then observed were due to
the circumstance that the electrodes were placed on
heterogeneous parts of the nerve, as I shall be able
to shew presently.

>» Mutzer’s Elements, pp. 686—689.
¢ Traité des Phénoménes Electro Physiologiques, p. 253.
CHAP. XI. §. 1. THE GALVANOMETER. 137

My more recent experiments may be classed
under three heads: Ist, Those in which the galva-
nometer was employed; 2nd, Those in which the
galvanoscopic frog was used; 8rd, Those in which a
magnetized needle was used.

Sect. I. The Galvanometer.

The animal, most frequently a rabbit, but occa-
sionally a guinea-pig or a frog, was pithed, or
rendered insensible by means of prussic acid. The
sciatic nerve was carefully exposed throughout its
whole course, and a plate of thin glass passed
beneath it. All traces of blood being carefully
removed, the pointed extremities of platinum elec-
trodes were inserted at the extreme ends of the
exposed nerve, as far apart as possible, leaving,
however, a small portion, just at its exit from the
pelvis, for the purpose of serving as a. point of
irritation. The leg of the limb was fastened down
so as to prevent a too great motion during con-
traction, which might otherwise disturb the position
of the electrodes. The other ends of the electrodes
rested on and dipped into wooden cups containing
mercury, the cups being placed upon glass for
insulation: by these means a slight motion of the
electrodes would not disturb the galvanometer, and
it remained perfectly steady. The galvanometer
consisted of several coils.

At first the nerve was irritated with the point of a
steel needle, which was insulated, being inserted by
138 NERVE FORCE. CHAP. XI. §. 1.

means of a cork into a glass tube, which formed the
handle; but, as may be readily supposed, the action
of the steel needle upon the needles of the galva-
nometer so interfered with the results, that it was
obliged to be set aside, and a pointed piece of
copper wire, or a piece of glass or a glass pen, was
used for the purpose.

The experiment thus arranged, the nerve was
then irritated, and the muscles of the limb made to
contract; but no effect occurred upon the needle.
When, however, one electrode remained in the
nerve, and the other was placed on its external
surface, then the ordinary effect, the nerve current,
was produced, the nerve during this period not
being stimulated to action: if the nerve was stimu-
lated and the muscles contracted, there did not
appear to be any effect upon the needle indicative of
an increase in the nerve current, or even of a sudden
decrease in it, the needle gradually receding to its
former position. The nerve was divided at its
lower extremity, one electrode brought into contact
with the divided surface, and the other with the
longitudinal surface; the effects were the same; the
nerve current appeared, but after that, there was no
increase or indication of a current upon stimulating
the nerve.

It will be readily seen, that two questions are
involved in this last experiment: ist, Is a nerve,
during nerve action, traversed by a current of
electricity? which we are now considering: and,
CHAP. XI. §. 1. THE GALVANOMETER. 139

2ndly, Is the nerve current affected during nerve
action? a question which will be considered
further on.

In other experiments the abdomen was laid open,
so as to expose the lumbar plexus of nerves, and
the nerves excited by a current from a pair of
Grove's cells, so as to produce a more powerful
contraction of the muscles ; the effects were negative,
so long as the electrodes remained in their first
position in the nerve; but if, from the motion of the
limb, or intentionally, the electrodes were moved,
so as to be in contact with heterogeneous parts of
the nerve, then vibrations of the needle were occa-
sionally produced. The spinal cord was irritated in
the lower part of the dorsal region, by passing a
copper wire between the vertebra, so as to excite
contraction, but the results were still the same.
The nerve was excited by touching it with caustic
potash, without any effect being produced upon the
needle of the galvanometer; but if the alkali came
into contact with one of the electrodes, then an
effect occurred upon the needle, evidently due to
the chemical action thus set up.

The animal was poisoned with strychnine, and as
soon as tetanic contractions occurred, the experiment
was repeated, but with the same negative results.

The only conclusion to be drawn from these ex-
periments is the following: That when the electrodes
of a galvanometer are inserted IN a nerve during nerve
action, there is no manifestation of current force; but if
140 NERVE FORCE. CHAP. XI. §. 1.

the electrodes come in contact with heterogeneous parts
of the nerve, during nerve action or not, then current
force is manifested ; this effect being, however, the result
of the so-called NERVE CURRENT.

Szcr. Il. The Galvanoscopie Frog.

The galvanoscopic frog is, unfortunately, accom-
panied with great uncertainty in its indications, and
consequently requires the greatest care in its em-
ployment. The delicacy of its indications does not
always correspond with its freshness; the muscles
may be easily excited to contract when first prepared,
but immediately afterwards it may be difficult, or
even impossible, to arouse the contractions. This
difficulty may arise from the muscles having once
contracted remaining so. Again, a limb which is
not very delicate in its indications at first, may,
after some little time, be all at.once seized with
slight tetanic contractions ; this circumstance may
arise from the nerve becoming dry, as has been
already pointed out by MarsHatt Hatu*. There
are other circumstances which are undoubtedly in-
fluential, and amongst them the vital condition of
the animal. It has frequently happened to me, that
a limb which has been laid aside as worthless, has
subsequently proved upon trial to be most delicate
in its indications, without my being able to account
for it. The muscles should be neither flabby nor
too much contracted. The only test to be relied

4 Edinburgh New Philosophical Journal, April, 1848.
CHAP. XI. §. 11. THE GALVANOSCOPIC FROG. 141

upon is, by occasionally trying the limb with some
well-known source of electric action, such as the
muscle or nerve, and to have several at hand in case
of emergency.

The former experiments were now repeated, and
the nerve of the galvanoscopic frog, its limb being
supported on a piece of glass, was laid at one time
transversely on the sciatic nerve, at another time
longitudinally on the nerve, and the nerve then
irritated as before, but no effect occurred upon the
galvanoscopic limb. If the galvanoscopic nerve be
placed carelessly upon the other nerve, so that its
end and side touch the nerve, and thus form a
circuit, then the galvanoscopic limb will contract,
this being the result of the nerve current in the
galvanoscopic frog acting upon its own muscles;
the effect being over, and the nerve remaining in
this position, no contraction occurred upon stimu-
lating the sciatic nerve; but upon opening the circuit
of the nerve, it occasionally happened, if the frog
was delicate in its indications, that contractions
ensued. Should there be any blood upon the nerve
of the animal, and the nerve of the galvanoscopic
limb touch it and the nerve, then the galvanoscopic
limb will contract; this may be considered as the
result of a current arising from the contact of hete-
rogeneous substances. But in neither instance was
the effect any thing like that which occurs when
the galvanoscopic nerve is placed upon a tetanized
muscle.
142 NERVE FORCE. CHAP. XI. §. II.

Neither Mutzer* nor Marreuccr® have been able
to obtain any effect when they placed the galvano-
scopic nerve upon another nerve in a living animal.

The sciatic nerve of the animal was now divided
at its lower extremity, and the nerve of the galvano-
scopic limb arranged thus: its divided extremity was
placed in close contact with that of the animal, and
then brought round so that its side should be in
contact either with the side of the nerve of the
rabbit, or with that of its own nerve, forming a loop.
Now if there was any thing like a current passing
along the excited nerve of the animal, we should
expect it to be continued on along the nerve of the
galvanoscopic frog, producing the effect of a direct
current. The galvanoscopic limb contracted when
first applied, due either to its own nerve current,
or to that of the animal, but no contraction occurred
during the stimulation of the nerve, unless the
circuit was broken. Instead of the side of the nerve
of the galvanoscopic frog being placed in contact
either with its own nerve or that of the animal, the
tendo Achillis was used: the effects however were
still the same, no contraction during the stimulation
of the nerve. When the end of the nerve of the
galvanoscopic frog was merely placed in contact with
the end of the sciatic nerve, so as to form a pro-
longation of the nerve, no contraction of the galvano-
scopic limb occurred. The divided ends of the
sciatic nerve of the animal were brought into as close

© Loe. cit.
CHAP. XI. §.111. THE MAGNETIC NEEDLE. 1438

contact as possible by bending the limb upon the thigh,
and the nerve then stimulated at its upper part, but
there was no contraction produced in the lower limb.

The same conclusion may be drawn, and the same
remarks made, in regard to the galvanoscopic frog,
as were made in regard to the galvanometer, viz.
when the proper precautions were taken, no evidence
indicative of the manifestation of CURRENT FORCE in
@ nerve DURING nerve action could be obtained.

Secr. III. The Magnetic Needle.

It may be readily supposed, that if we failed to
obtain any evidence of the existence of current force
in a nerve during nerve action by means of the
galvanometer, it would most probably happen that
the magnetic needle would also fail to detect it. To
exhaust every possible mode of its detection, the
following experiments were undertaken. I may just
add, that Prevosr, Dumas‘, and Mutirr‘’, have
already performed similar experiments, but failed in
obtaining any result.

A small magnetised needle, three quarters of an
inch in length, was suspended by means of a single
fibre of silk-worm silk, the needle being passed
through a strip of card, and to this the silk was
attached. To avoid motion of the needle from slight
draughts of air, and from vibration of the room, the
silk was attached to a firm support, and a glass tube,
an inch in diameter and five inches in length, was

i Loe. cit.
144 NERVE FORCE. CHAP. XI. §. IIL.

so arranged as to inclose the needle. The sciatic
nerve being laid bare, a plate of glass was placed
beneath it, and thus the nerve was elevated above
the surrounding muscles; it was then brought
beneath the magnetic needle, and kept in that
position, being supported upon a stool about .a
quarter of an inch below it. The nerve was placed
in various positions with regard to the needle, some-
times parallel, at other times transversely or ob-
liquely to it. The needle being perfectly steady, the
muscles of the leg were made to contract, as in the
previous experiments; but, in whatever manner the
experiment was arranged, there was no indication of
any action upon the needle. Whenever any motion
of the needle occurred, it was evidently due to the
motion of the atmosphere produced by a too ‘great
motion of the limb. I may also observe, that, as the
experiment was performed near a window, it was
necessary to guard against the heating effects of the
sun’s rays upon the air within the tube. To the
importance of attending to this latter circumstance
in these experiments I have already alluded.

Can we magnetise a needle? Thick and thin needles
about three quarters of an inch long, and free from
magnetism, were inserted either transversely or longi-
tudinally in the nerve, and the muscles then made to
contract powerfully, and for some time by means of
an electric current from two of Grove’s cells. In
these experiments there was no distinct evidence of
CHAP. XI. NOT CURRENT FORCE. 145

the needles having become magnetised. Upon
testing the needles after the experiment with steel
filings, it was frequently observed that the filings
adhered to the needles throughout its whole extent,
although they had been previously wiped with a dry
clean cloth. These effects were evidently due to the
needle being damp; the moisture from the fingers
was sufficient to produce this damp state, and the
only mode of preventing it was by heating the
needle, but by so doing, any magnetic state it might
possess would be destroyed. The difference ob-
served in the needles in which the filings adhered
when magnetised or when damp is very great; in the
latter the whole surface is slightly covered with
them, but in the former the filings are confined tu
one or two spots.

The results of the present investigation only tend
to confirm the opinion already expressed by Murer,
Marvevccr, and others, that nerve force is not iden-
tical with current force. Or the conclusion may
perhaps be more correctly expressed by saying, that
we have not been enabled to obtain any evidence of the
manifestation of current force in a nerve during nerve
action. It must be borne in mind, however, that
I am now speaking of nerve action, and not dis-
proving the existence of the so-called nerve current
which is manifested in a nerve during its quiescent
state: and this brings before us another most
important question for consideration, viz. Is this
nerve current affected during nerve action ?

L
146 NERVE FORCE CHAP, XI.

In De 1a Rive’s valuable Treatise on Electricity ¢,
and to which I must refer, as containing perhaps the
most recent views in regard to this question, will be
found the following important remarks: ‘‘ We know,”
says Ds xa Rive, “ that the nerve possesses of itself
a certain electrical state, which we have succeeded
in determining ; we know, moreover, that this electric
state is modified by every excitation exercised upon
the nerve..... Now if by any cause whatever the
electric state of the nerve is modified, equilibrium
is destroyed; and from this there results a con-
traction of the muscle, or a sensation. Before
studying the consequences of the modification, we
may remark, that it consists in the fact that the
organic molecules of which the nerve is formed are
not polarised transversely from within outwards, but
longitudinally from one extremity to the other, as is
every conducting body traversed by an electric cur-
rent. When the modification arises from the imme-
diate action of the nervous centre, it appears that
the polarisation is brought about always in such
a manner, that the negative poles of the molecules
are turned on the side of this centre, and the positive
on the side of the muscle, as would result from the
action of an electric current that might be travelling
in the direction of the nervous ramifications. This it
is that explains why an electric current which travels
in this direction favours the contraction much more

s A Treatise on Electricity, by Aug. De La Rive. Translated
by C. V. Wager, F.R.S. vol, iii. p. 56.
CHAP. XI. NOT CURRENT FORCE. 147

than when it travels in the contrary direction. This
is equally a natural consequence of the fact, that the
particles of the nerves upon which the immediate
action of the brain must be exerted, being the
interior which penetrate into it more deeply, have
their negative poles free.

“Tf, instead of coming from the brain, the action
exerted upon the nerve comes from the muscle, the
polarisation of the nerve must take place in a
contrary direction, namely, so that the positive poles
are all turned towards the side of the nervous
centre, and the negative towards the side of the
muscle whence the excitation comes.” I have
quoted these observations at some length, as con-
taining perhaps the most recent views upon the
subject, and supported by an authority of some
weight. Now the only conclusion that appears to
me that can be drawn from these remarks is this,
that the force transmitted along a nerve during nerve
action is identical with current force as it exists in a
wire carrying a current of electricity. If so, I need
scarcely add, that we ought to be enabled to obtain
some direct experimental evidence in support of this
opinion: at the present time I know of none beyond
that advanced by Du Bors Reymonp, who appears to
have ascertained in his experiments, that the nerve
current may be made to increase or diminish according
as the nerve is excited by an electric current—being
increased if the current passes in one direction, and
diminished if it passes in the contrary direction.
148 NERVE CURRENT CHAP. XI.

T have already had occasion to relate some experi-
ments in chap. ix. in which I endeavoured to obtain
an increase of the nerve current according to the
mode suggested by Du Bois Rermonp, but entirely
failed in doing so. As they were not undertaken
for the express purpose of ascertaining whether the
nerve current is affected during nerve action, the
following were performed.

Is the nerve current affected during nerve action?
Instead of employing a nerve separated from the
animal, the experiments were conducted in a manner
similar to those that have been already related in
the previous part of the present chapter, viz. with
the sciatic nerve. The electrodes of platinum were
coated at one extremity with shell-lac, leaving, how-
ever, the extreme end bare, and one of them was
pointed so as to be easily inserted into the sub-
stance of the nerve, whilst the other electrode
presented a flat surface to rest upon the surface
of the nerve. The distance at which -the electrodes
were placed from each other varied from an inch to
a quarter of an inch, but were generally within about
half an inch of each other. When the needle indi-
cated the existence of the nerve current, the upper end
of the sciatic nerve was stimulated either by means of
the glass pen, or copper wire, or an electric current,
to produce muscular contraction in the leg: some-
times the nerve was stimulated by a constant current,
at other times by an intermitting current. The
current was passed at one time as a direct current, at
CHAP. XI. NOT AFFECTED DURING NERVE ACTION. 149

another time in the inverse direction. Now in
whatever manner the nerve was excited to action,
I failed to obtain any evidence of a decided increase
in the nerve current, neither could I obtain any
definite indication of a sudden decrease in the nerve
current; the needle gradually receded. Vibrations
of the needle were frequently observed, and were
evidently due to the motion of the electrodes caused
by the movement of the limb during the contraction
of the muscles. The effects upon the needle were
just the same, in whatever position the electrodes of
the galvanometer were placed ; whether the electrode
in contact with the surface of the nerve was placed
on the upper or lower portion of the nerve, between
the stimulated portion of the nerve and the other
electrode, or below the latter. There was no de-
’ eisive action upon the needle in these experiments
indicative of any marked influence over the nerve
current; the needle merely returned to its former
position, or gradually receded.

When the galvanoscopic frog was employed, as in
Sect. IJ., after the first effect of the nerve current
was over, there was no further contraction, however
long the nerve was stimulated; there was no effect
corresponding to the tetanized muscle; it was im-
possible to produce a tetanic condition of the nerve,
so that it should affect the nerve of a galvanoscopie
frog},

b What the condition of the nerve may be along which the
inverse current has passed for some time, so as to produce
150 NERVE FORCE. CHAP. XI.

I should eertainly hesitate before coming to the
conclusion, that no effect is produced upon the
nerve current during nerve action; but I certainly
have not been able to obtain those definite and
constant indications that we have a right to expect,
under the supposition that the nerve current, as
manifested in the transverse direction of the nerve,
is converted during nerve action into a current in
the longitudinal direction of the nerve, which appears
to be the opinion of Ds 1a Rive, as expressed in the
remarks I have already quoted.

Concluding Remarks.

The conclusions that we have arrived at in the
present investigation being of a negative character,
may perhaps be considered as any thing but satis-
factory. Let us not, however, be led away by the
false supposition, that because negative results have
only been obtained, that therefore no positive know-
ledge is acquired: we may have ascertained a most
important fact, if true, and, whether true or not,
may partly depend upon our being able to give a
satisfactory reason for our failures. Have we not,
it may be asked, commenced our inquiry with a
false notion in regard to nerve action; viz. its
identity with electric action? Have we not sup-
posed an identity to exist between current force
and nerve force, which we have failed to prove?

tetanic contractions in its own limb, I have not been able to
ascertain; there is no increase in the nerve current.
CHAP. XI. CONCLUDING REMARKS. 161

To suppose that the conditions may exist in the
one case and not in the other, and that the two
forces may still be the same, cannot be deemed
satisfactory to any experimentalist. If nerve force
be electric force, we have a right to ask for some
proof of it. The circuit form of the arrangement
exists in the transverse direction of a nerve, and we
can detect the necessary current, the so-called nerve
current. The effects here, however, are analogous
to those of a charged Leyden jar rather than to a
voltaic circle, as I have endeavoured to shew in
previous chapters, and to which I have already
referred. The very circumstance of our being able
to shew this state in the transverse direction, would
lead us to expect that we ought to be able to prove
its existence in the longitudinal direction, if it
existed.

The subject under consideration involves, how-
ever, three distinct questions. Ist, Is nerve force
nothing more than the electric force which exists in
the nerve, and put into motion during nerve action?
or, 2ndly, Is this electric force in the nerve converted,
as it is called, into nerve force during nerve action?
or, 8rdly, Is this electric condition of the tissue
merely a condition, and perhaps a necessary con-
dition, for the manifestation of nerve action ?

In reply to the first question, it may be observed,
that my experiments have failed to give the necessary
proof in favour of this supposition.

In regard to the second question, if we could
152 NERVE FORCE. CHAP. XI.

obtain any decided evidence of the nerve current
being affected during nerve action—I say decided—
then we should be called upon to account for its
inerease or decrease, according to the principles of
conservation of forcei, and to shew what has become
of the force. But if the effects that have been
obtained with the galvanometer, viz. a gradual decrease
in the nerve current, such as I have observed, be
due merely to a disorganization of the nervous tissue,
and they are such as are consonant with this sup-
position, then nerve force must be ranked as a higher
form of force, and the electric condition of the tissue
merely a condition for the manifestation of nerve
action. To assist in elucidating this question, let
us just refer for a moment to the muscular current,
and see whether this current is affected during
muscular contraction.

When the electrodes of a galvanometer are so
arranged with the muscular fibre, viz. in contact
with the transverse and longitudinal sections, the
muscular current is produced; upon making the
muscle contract, the needle returns rapidly to its
former position, and passes beyond it. Du Bors
Reymonp has designated this effect, “the negative .
variation of the muscular current ;” the exact mean-
ing of the phrase I do not comprehend, if it be
intended to express more than the fact. The
question, however, is this, Is the return of the

i On the Conservation of Force. By Prof. Farapay. ‘* Philo-
sophical Magazine,” April, 1857,
OHAP. XI. CONCLUDING REMARKS. 153

needle in consequence of one of the surfaces of the
muscle separating from the electrode during the
contraction of the fibre, and so breaking the circuit ;
or is there a sudden diminution in the electric
tension of the tissue, and so producing a decrease
in the muscular current? Now we have some
evidence that there is a discharge of electric force
during muscular contraction, as shewn by the galva-
noscopic frog in Marrgucel’s experiments; but we
have no evidence that the muscular current is in-
creased in these experiments during muscular con-
traction. The loss of force, the lowering of the
electric tension of the muscular tissue, which takes
places during contraction, is restored by nutrition*.
If we can detect the evolution of electric force
in the muscular tissue during muscular action,
surely we ought to be able to obtain some evidence

k According to the principles of the Conservation of Force, we
must endeavour to trace out in what manner the force in the
muscle is disposed of. We have heat developed during muscular
contraction, as shewn by BrcqurrEL, and Brescuer, and
Martrevecr. Carbonic acid is evolved during muscular con-
traction, as shewn by Marreuccr in his experiments on mus-
cular respiration. Electric force is evolved during muscular
contraction, as has been proved by Marrevcci, and confirmed
by others, and also by some of my own experiments. It would
be, perhaps, erroneous to suppose, that the force is converted
into chemical action, as nutrition; nutrition is undoubtedly
increased during continued muscular exertion; but muscular
action—contraction—would appear to be the first act in this
series of events, and nutrition the second; contraction may be
considered as the exhausting act, nutrition the restoring act,
in this process.
154 NERVE FORCE. CHAP. XI.

of the manifestation of electric action in the nervous
tissue during nerve action, if nerve action be, as it
is supposed to be, merely the result of the electric
force of the tissue being converted into current
force.

Let us not hastily conclude that nerve force is
totally distinct from electric force, or that it bears
no relation to it or the other polar forces, such as
magnetism, for example. We appear to be in a
position somewhat similar to the physical philo-
sophers prior to the discovery of Farapay of magneto-
electricity. So long as they confined their experi-
ments to the mere application of the electrodes of
the galvanometer to the two ends of the magnet,
no result was obtained; the necessary evidence, the
connecting link, was wanting; and we may now be
in a somewhat similar position. Iam not now sup-
posing, or going so far as to say, that it must be by
means of the galvanometer that this necessary evi-
dence, the connecting link, is to be obtained; it may
be by some other fact totally unconnected with the
galvanometer that the connection will be shewn.
We have sufficient evidence, however, to shew, that
an intimate connection exists between nerve force and
electric force, viz. in the development of the electric
force in the fish, in the dependence of the former
upon the will of the latter. We may also refer to
the relation that exists between nerve force and
muscular force. We have strong evidence for be-
lieving that muscular force is a polar force; the
OHAP. XI. CONCLUDING REMARKS. 155

electric condition of the tissue and the development
of the force during contraction is in favour of the
supposition. We are not compelled to assume that
any peculiar force exists, or is associated with the
muscle distinct from this electric force; only that the
mode in which it exists is brought about by other
agencies than those that occur in the inorganic
kingdom, viz. by nutrition. It is in these intimate
relations and: connections in the dependence of the
developement of electric force in the fish, and of
muscular contraction upon nerve action, that the
strongest evidence for the polar character of nerve
force is manifested, and not so much upon the
electric condition of its tissue’.

But, it may be asked, are we justified in sup-
posing that nerve force, in nerve action, is entirely
independent of the electrie force as it exists in the
nerve in its quiescent state? Do we not see, that
nerve force bears some relation to the state of the
vital powers of the animal, viz. its nutrition? as
nutrition is increased or diminished, does not
nervous energy increase and diminish in a cor-
responding ratio? and have we not experimental
evidence to shew, that the electric state of the tissue
(the nerve current) is dependent upon, and varies

' We must not overlook the connection which exists between
nerve force and secretion. The latter is undoubtedly a polar
action, but the influence of nervous action over secretion,
although it undoubtedly exists, does not appear to be exerted in

so immediate and direct 2 manner as in the two instances I
have just quoted.
156 NERVE FORCE. CHAP. XI.

according to, the state of nutrition of the nerve
tissue? Do notall these facts shew, that an intimate
relation exists between these two forces—between
the electric force in the tissue and the nerve force—
and therefore what right have we to suppose that
any other force but the electric force is connected
with the nerve?

All this may be granted, but the premises do not
justify the conclusion. There may be no necessary
connection between the electric state of the tissue and
nerve force beyond that of being a condition, and
perhaps a necessary condition, for the manifestation
of nerve force. I will not go so far as this, and say
that the electric force of the nerve has no connection
whatever with nerve force; but only this, that nerve
force is not merely the electric force of the tissue
converted into current force, as it has been supposed.
Whether the electric force of the tissue is converted
into nerve force during nerve action is another
question, and perhaps the question for us to solve.
At present, we have no experimental evidence to
prove this supposition; for we have not obtained
any indication of a decided loss in the electric state
of the tissue, a sudden decrease in the nerve current
during nerve action, to indicate such a conversion.
The evidence, however, is not sufficiently decisive
of the question, and at present it may be considered
an open one™

™ T have not thought it necessary to adduce other well-known
evidence to shew the difference between the action of nerve
CHAP. XI. CONCLUDING REMARKS. 157

It must be remembered, that we have hitherto
limited our views, and have been comparing nerve
foree with only one of the ordinary polar forces with
current force. Let us now compare it in regard to
magnetic action. In a magnet we can get no evi-
dence of current force travelling from one pole to the
other; the force exists in a state of tension, which
may be raised or lowered without affecting the
galvanometer when arranged with the electrodes at
the two ends. May not nerve force exist in a state
of tension, and nerve action correspond with a rising
or lowering of this state, just as the muscular fibre
may be regarded as existing in a state of electric
tension and muscular contraction, the result of a
lowering of its tension? The developement of the
force in the fish, and other facts, may perhaps be
adduced as an argument against this supposition,
and in favour of transmission of force from one
point to another along the nerve. But even here an
increase or a lowering in the tension of one part
may be accompanied with a lowering or an increase
in the tension of another part; the final result being
tantamount to the transmission of force from one
part to another. Still it behoves us not to keep
limiting our views to one class of actions only, but
to be bold and suggestive, and seize upon any
resemblances, however slight; and provided we do

force and of current force. The ligature of a nerve preventing
the transmission of nerve force, is a strong argument against
the identity of these two forces.
158 NERVE FORCE. CHAP. XI.

not allow them to take a too firm hold of our minds,
so as to lead us to consider them as realities, but
merely suggestive, by leading to future experiments,
we may hope to arrive ultimately at some more
promising and positive results.

The following conclusions may be deduced from
the present inquiry.

First, That nerve force, during nerve action, is not
current force.

Secondly, That the electric condition of the nerve,
as manifested by the nerve current, is not converted
during nerve actign into currrent force.

Thirdly, That the electric condition of the nerve
may be merely a condition, and perhaps a necessary
condition, for the manifestation of nerve action.

Fourthly, That the evidence in favour of nerve
force being polar, is shewn by the connection that
exists between the developement of the electric force
in the fish and its dependence upon the will of the
animal, and also in the connection between nerve
action and muscular action, the latter being regarded
as polar.

Fifthly, That the whole of the evidence indicates
that nerve force is of a higher character than any of
the other known forms of polar force. And,

Siathly, The question, whether the electric force,
as it exists in the nerve, may not be converted into
nerve force during nerve action, may be considered
at present an open question.
CHAP. XII.

ON THE MANIFESTATION OF CURRENT ELECTRICITY IN
PLANTS DURING VEGETATION. IN THE LEAVES; IN
THE ROOTS; IN THE PETALS; AND IN FRUITS AND
TUBERS,

Tuar electric currents may be obtained by insert-
ing the platinum electrodes of a galvanometer into
different parts of vegetables, has been proved by
BrcquereL*, Donne’, Wartmann’, ZANTEDESOHI4,
and Burre. According to Brcquzren’, “The dis-
tribution of the ascending sap, and the liquid of the
cortical parenchyma, leads to the belief that currents
continually circulate in vegetables, from the bark to
the pith.” .. . “ The leaves act like the green part of ,

a Traité de l’Electricité, tome iv. p. 164; Comptes Rendus,
Nov. 4, 1850, Mai 5, 1851; or Philosophical Magazine, 1851;
Mémoires de Académie des Sciences de Paris, tome xxiii.
p. 301, 1853. I may refer also to a valuable Paper by Professor
Goopstr, in the Edinburgh New Phil. Journal, Oct. 1855.

> Traité de l’Electricité, tome iv. p. 164.

¢ Bibliothéque Universelle de Genéve, Dec. 1850; or Philo-
sophical Magazine, 1851.

4 In the Comptes Rendus for Mars 24, 1851, ZanrEpEScuI
refers to the Comptes Rendus des Sciences de l'Institut Vénitien
des Sciences, Lettres, et Beaux Arts, 26 Mai, 1850, as contain-
ing the results that he has arrived at. I have been unable to
meet with this publication.

© Philosophical Magazine for Feb. 1854, and Annales de
Chimie et de Physique, 3™¢ Serie, tome xli. p. 198.

f Philosophical Magazine, 1851, p. 578.
160 CURRENT ELECTRICITY CHAP. XII.

the parenchyma of the bark; that is to say, the
sap which circulates in their tissues is negative with
relation to the wood, to the pith, and to the earth,
and positive with regard to the cambium.”....
“The chemical actions are the first causes, it cannot
be doubted, of the electric effects observed in
vegetables.”

“Tn the roots,” says Warrmann$, “ the stems, the
branches, the petioles, and the peduncles, there
exists a central descending current, and a peripherical
ascending current; I call them azial currents.” ....
“In most leaves the current proceeds from the
lamina to the nerves, as well as to the central parts
of the petiole and the stalk. In certain fleshy
-plants, it is directed from the medullary or cortical
portions of the stalk towards the mesophyllum, and
from the latter towards the superior and inferior
surfaces.”....‘‘ They arise from an electro-chemical
action between the liquid substances brought into
contact by the tearing of the tissues. The weak
residual current (which is the normal current) owes
its origin to the interposition of the porous vegetable
walls between juices of different concentration, and
proceeds through them from the densest to the least
dense liquid.”

The general conclusion that Proressor Burr ap-
pears to have arrived at is the following: “ The roots,
and all the internal portions of the plant filled with sap,
are in a permanently negative condition ; while the moist

8 Philosophical Magazine, 185].
CHAP. XII. IN PLANTS DURING VEGETATION. 161

or moistened surface of the fresh branches, leaves, flowers,
and fruits, are permanently positively electric.” ...
He considers that ‘the electro-motive action arises
from the moist surface of the plant on the one hand,
and the liquids which are in its interior on the
other.”

The results of these inquirers would lead us to
suppose, that the effect upon the needle is due to
what may be termed secondary actions, viz. to the
reaction of the different vegetable juices upon each
other, and to the reaction of the fluids upon the
surface of the platinum electrodes. The very fact,
however, that a difference in the fluids exists, proves
also that a force capable of causing this difference
must likewise exist; and the question. naturally
arises, are not these primary actions accompanied
with the developement of electrical actions ?

The primary actions I refer to are those of secretion,
nutrition, and. absorption. Now as the leaves and the
roots perform some of the most important functions
in plants, it appeared probable that it would be in
these organs that we might obtain a solution of our
problem; and the two following questions now oc-
curred: Ist, What would be the effect if the external
surface of the leaf, and the sap flowing from it, be
formed into a circuit? and, 2dly, What would be the
effect if the external surface of the root (the spon-
gioles) and the fluid ascending from it be formed
into a circuit?
162 CURRENT ELECTRICITY CHAP. XII. §.1.

Sor. I. On the Manifestation of Electrie Currents in
the Leaves of Plants during Vegetation.

The mode of conducting the experiments was as
follows: The leaf was placed upon a clean piece of
glass, and the extremity of one platinum electrode,
to the extent of half an inch or an inch, was placed
upon the upper or under surface of the leaf; a small
notch was cut in the petiole, and, as the sap flowed
out, the extremity of the other electrode was placed
in contact with it.

I may just remark, that after having worked for
some time upon plants growing in pots and in
London, I was led, from the unsatisfactory results
that were obtained, to repeat the experiments upon
plants growing in the open air and in the country;
and it soon became evident that, in order to obtain
any thing like satisfactory results, strong, healthy,
and vigorous plants should be employed}.

Experiment 1. Vegetable marrow. A healthy
middle-sized leaf, and the sap from the petiole; the
latter positive’ 3°. <A large leaf slightly tinged with
yellow, and dry, and the sap from the petiole—no
effect. Various leaves were tried with similar results;
when any effect was obtained, the sap was positive.

5 The experiments were performed during the months of
July, August, and September, 1852,

‘The difficulty experienced in comprehending the results
obtained by different inquirers in reference to the direction of

the current I have already alluded to in chap. x.
CHAP. XII. §.1. IN LEAVES DURING VEGETATION. 1638

The surface of the leaf was occasionally moistened
with water, with doubtful results as to the effect
being increased. If the leaf had been separated
from the plant for any time before the circuit was
formed, no effect occurred.

As several of the experiments were carried on in
the open air, one or two circumstances occurred
which it was necessary to guard against. If the
weather was at all boisterous, it became utterly im-
possible to continue the experiments, the slightest
breeze being sufficient to shake the instrument. To
obviate this difficulty, the galvanometer was firmly
fixed upon a heavy block of wood, and sheltered.
I was, however, perplexed by another circumstance.
Working during a fine and calm day, it occasionally
happened, that, just upon the point of completing
a circuit, the needle would move to the extent of 10°
or 15°, or more, without any apparent cause, the
needle up to that time having been perfectly steady,
and the circuit not yet completed. After some time
it was noticed to occur just after a cloud had passed
over the sun, and it was thought to be due to a
slight breeze that might be then produced; but I am
now disposed to consider if as owing to the heating
effect of the sun's rays upon the glass shade of the
instrument creating a motion of the air within the
shade. Some facts bearing upon this question have
been noticed by Pror. Tyxpat* in reference to some
experiments of Dr. Goopmay.

k Philosophical Magazine, Feb. 1852,
164 CURRENT ELECTRICITY CHAP. XII. §.1.

Another fact worthy of notice may be mentioned.
As the galvanometer was frequently obliged to be
moved into the neighbourhood of the plant, it would
sometimes happen, from the altered position of the
instrument, that the plane of the coil would be in
the reverse direction of that of the needles to which
it had been previously; hence contradictory results
would very readily be supposed to be obtained.

To avoid unnecessary repetition, I shall generalize
the results that were obtained in the following
experiments. They were conducted in the same
manner as in the first experiment, and upon leaves
of different varieties of the following plants:
cucumber, vine, lettuce, cabbage, nasturtium, con-
volvulus, rose, ivy, hop, walnut, geranium, fuchsia,
strawberry, bean, apple, ficus elastica, ficus carica,
lemon, orange, oleander, eutaxia, camellia, mesembry-
anthemum, lily, marvel of Peru, pirus japonica,
tropeolum, wistaria, elder, sycamore, hollyhock,
arum, hydrangea, thistle, and dahlia. In some the
effects were null, in others but slight; the greatest
effect obtained amounted to about 2° or 8°; the
electrode in contact with the sap, positive. The most
satisfactory results appeared with the firm, compact
leaves, such as the camellia, vine, elder, and syca-
more, and when the electrode was in contact with
the under surface. It frequently happened, that, in
experimenting with different leaves of the same
plant, effects might be obtained with one leaf but
not with another, although in other respects perfectly
CHAP. XII. §.1. IN LEAVES DURING VEGETATION. 165

similar’. This circumstance may be adduced as
shewing, that the effect upon the needle cannot be
entirely referred to the changes which occur in the
sap from exposure to the air; and the question now
arises, To what actions can we refer these effects?
Is the sap acid, or does the sap contain a cation ?

I shall not enter into any discussion as to the
functions of leaves, whether they may be considered
as organs of respiration, digestion, or absorption,
but refer my readers to works on physiological
botany. That oxygen gas or carbonic acid gas is
given off by the leaves of plants, may be considered
as having been experimentally proved.

If we break off the petiole of a leaf, and just touch
a piece of litmus paper™ with the divided surface, in

' It is probable that the circumstance of not obtaining any
result upon some of the leaves, might depend upon their
not being always in the same state of action. Some experi-
ments on the Respiration of the Leaves of Plants, by Mz. Prpys,
bearing upon this question, will be found related in the Phil.
Trans. for 1848, p. 829.

m In the employment of litmus as » test we must bear in
mind, that a compound might shew an acid reaction, without
possessing at the same time an excess of acid. According to
Berzelius, “ the colour of litmus is naturally red, and it is only
rendered blue by the colouring matter combining with an
alkali. If an acid be added to the blue compound, the colouring
matter is deprived of its alkali, and thus, being set free,
resumes its red tint. Now on bringing litmus paper in
contact with a salt, the acid and base of which have a weak
attraction for each other, it is possible that the alkali contained
in the litmus paper may have w stronger affinity for the acid of
the salt, than the base has with which it was combined; and in
166 CURRENT ELECTRICITY CHAP. XII. §. 1.

the majority of instances the sap will be found to
have an acid reaction; in some succulent plants the
effect will be null or very trifling, whilst in other
plants, such as the vine, it will be very apparent.
In the latter instances, the effects upon the needle
may be fairly referred to the acid reactions of the
secretions of the plant; but can we refer them to the
same action when the sap does not present an acid
reaction? Are we sure that the sap is acid? May
not this acid reaction upon the litmus arise from the
acid secretions of the plants, which become mixed
with the sap upon the tearing asunder of the tissue
of the plant?

The difficulty which arises in solving some of
these questions occurs from the fact, that there is
not that distinct circulation in plants as in animals;
the sap, as it passes from one spot to another, may
undergo a series of progressive changes, and in the
tearing and cutting of the tissues, a mixture of sap
from different parts and of secreted products must
naturally occur. We cannot place our electrodes
at the real acting point; there may be several acting
points between the electrodes; and the resulting
effect upon the needle may be that of a differential
or of a combined current, according to circumstances.

Two solutions, one acid, consisting of 8 drops of
strong sulphuric acid to one ounce of water, the

that case the alkali of the litmus being neutralized, its red
colour will necessarily be restored.” Turner's Chemistry, p. 671.
5th Edit.
CHAP. XII. §.1. IN LEAVES DURING VEGETATION. 167

other alkaline, consisting of 120 drops of the liq.
potassee (Phar. Lond.) to one ounce of water, were
prepared, and used in the following manner: The
electrode to be placed in contact with the sap was
dipped into a portion of the alkaline solution, and
then applied to the cut petiole; this electrode was
still positive to the other, the effect, however, was
not increased; if the effects were due in the former
experiments to the acid reactions of the sap, we
should now have expected the electrode to be negative.
The experiment was repeated upon another leaf, but
with the acid solution; the effect was now very much
increased, and the electrode in contact with the sap
‘positive. Several other experiments of the same
nature were performed, the results of which I shall
generalize by stating, that whenever the electrode
was coated with the alkaline solution, whether it was
that in contact with the surface of the leaf, or that in
contact with the sap, with but few exceptions there
was.no decided difference as to the effect upon the
needle; but that whenever one of the electrodes was
dipped into the acid solution, this was always positive
to the other.

If the leaf was gathered, an electrode being in-
serted into the petiole, and the leaf then plunged
into a glass of water containing the other electrode,
it frequently happened that the electrode in contact
with the water was positive to the other, even if the
water was rendered alkaline. It appeared to occur
principally with the leaf of the bean (Windsor), and
168 CURRENT ELECTRICITY CHAP. XI. §.1.

the strong-scented leaves, such as the geranium,
&e.

In judging of the results obtained by means of
these solutions", we must consider their effect under
two points of view; Ist, as producing their own
chemical effect; and, 2ndly, as forming a better
conducting medium for the current. When the acid
solution was employed, there can be no doubt that
the current then obtained was due to the immediate
action of the acid upon the tissue and juices of the
plant; it always indicated its positive condition, and
with increased effect; but how shall we account for
the action of the alkali? This should have indicated
a negative condition, if the current was due to its
own immediate action; it was generally found, how-
ever, to indicate a positive state when in contact with
the cut surface of the petiole; and here I cannot
help believing but that it must have acted, under
these circumstances, as a conducting liquid.

From these experiments we may deduce the follow-
ing conclusions:

lst, That when the electrodes of a galvanometer
are brought into contact, one with the surface of a
leaf, and the other with the sap flowing from the
same leaf, an effect occurs upon the needle, indi-
cating the surface of the leaf and the sap to be in
opposite electric states.

» T need scarcely point out the importance of paying particular
attention in the use of towels, and to cleanliness, especially of
the fingers and hands, when employing these solutions.
OHAP. XII. §. 11. IN ROOTS DURING VEGETATION. 169

2ndly, That these effects cannot be referred entirely
to ordinary electro-chemical actions; but that,

3rdly, They may be referred in part to the organic
changes which take place in the leaf during vege-
tation.

Before quitting the subject in reference to the
leaves, I shall make one or two observations. I have
generalized the results of my experiments, and there-
fore, in their repetition, the same precise result
must not always be expected. We must bear in
mind, that in these experiments we are obliged to
have a fresh subject for every experiment, and it
is almost impossible to meet with that identity of
circumstances we could wish; here the physical
philosopher possesses advantages which are denied
the physiologist. The problem we are endeavouring
to solve is connected with the vital actions of the
part; these terminated, nothing but difficulties then
arise.

Szot. IT. On the Manifestation of Electric Currents in
the Roots of Plants during Vegetation.
Brcquere° states, that “currents exist going from
the pith and the wood to the bark, by the mediation
of the roots.”
According to Warrmann?, “ when the soil and any
part of a plant, visible or underground, is placed in
the circuit of the rheometer, we find a current directed

° Philosophical Magazine, 1851.
P Ibid.
170 CURRENT ELECTRICITY CHAP. XU. §. 11.

from the plant to the soil, which is thus positive with
relation to it.”..... “The superficial layers of the
soil are frequently positive relatively to those which
surround the spongioles.”

In several experiments, the facts observed by
BrcquereL and Warrmann were obtained, viz. the
electrode in contact with the soil was positive to that
in contact with the plant; but that the effect was in
a great measure due to the soil, was shewn thus,—
both electrodes were inserted into the soil, when
one was found generally to be positive to the other.
To obviate this difficulty, the electrode employed to
be inserted into the earth was coated with sealing
wax to the extent of three inches, leaving the ex-
tremity exposed for about a quarter of an inch.

Several experiments were performed upon plants,
such as different kinds of geraniums, fuchsias,
balsams, antirrhinums, lophospermums, and vege-
table marrows, growing in pots, in the following
manner: The coated electrode was inserted into the
soil, and a notch having been cut in the stem
about an inch above the earth, or the stem entirely
removed, the other electrode was then brought into
contact with the divided surface; sometimes the
electrode was inserted into the stem; the general
result was as follows: in a very few instances, with
a lophospermum and an antirrhinum, and one or
two geraniums, the electrode in contact with the trunk
of the plant, with the sap, was found to be positive
to the other; in many instances no decisive effect
CHAP. XII. §. Ir EN ROOTS DURING VEGETATION. 171

was obtained; but in the majority of instances the
electrode in contact with the soil was positive to the
other. The influence of the soil was shewn thus:
in those plants which had been recently repotted,
and the mould consisted of a mixture of sand and
peat earth, the effects were null, and the electrodes
when inserted alone in the pots indicated but slight
effects; whereas in those pots in which the earth
had remained some time, and consisted of common
garden mould, the effects were very decided. Damp-
ness of the soil also increased the effect.

As it was difficult to know when the electrode was
in contact with the spongioles, the following method
was adopted. ;

Broad beans (Windsor) were made to vegetate in
the dark in water, and in small glass jars containing
but a small quantity of mould. At different periods
of vegetation, the apex of the plumula or the stem
was removed close to the cotyledons, and a circuit
formed between the divided surface and the external
surface of the radicle; the latter was generally
positive; in some instances no effect ensued. Sup-
posing that the effects might arise from the acidity
of the soil, a-dilute solution of potash was poured
into the glass jar. Under these circumstances,
however, the electrode in contact with the soil was
positive to the other. The whole root was taken out
of the soil, and washed gently in water so as to
remove the earth, then placed in water, and the
circuit reformed; the electrode in contact with the
172 CURRENT ELECTRICITY CHAP. XIl. §. II.

water was still positive. According as the surface of
the root in the water was greater, so was the effect
upon the needle increased. The sap from the roots
reddened litmus paper.

Hyacinth and narcissus bulbs were made to vege-
tate in the usual glass vessels. The electrode in
contact with the water and at the extremities of the
roots was positive to the other when inserted into the
stem or bulb. The bulb was raised so as to leave
the fibrille alone in the water; the effect was much
diminished, and almost null. The water was rendered
slightly alkaline by means of potash; the effects were
still the same.

The sap in the fibrille and bulb reddened litmus
paper.

The same experiments were made as with the
leaves, namely, coating the electrodes with acid or
alkaline solutions. Whichever electrode was coated
with the acid, was always positive to the other.

Becqurre.! has made the following remark:
“ On obtient peu ou point d'effet, lorsque l'une des
aiguilles est dans le ligneux, prés de la moélle, et
lautre dans la terre.”

According to LixpLey', Brugmans has ascertained
that some plants exude an acid fluid from their
spongioles.

Some experiments are also related by BecquEREL‘,

4 In his first Memoir.

t Introduction to Botany, p. 229.
s Traité de l'Electricité, tome iv. p. 185.
CHAP. XII. §. II. IN ROOTS DURING VEGETATION. 173

in which it would appear that an acid is formed
during the germination of the seeds.

If any difficulty occurred in pointing out the
electro-positive element in the leaves, the same dif.
ficulty meets us here, and the question arises, Are
not the results which were obtained with the galva-
nometer rather the results of secondary reactions, in
the majority of instances, than those of the primary
actions (the normal results), and which I obtained
but in a few instances, viz. when the sap indicated a
positive condition? The very circumstance of an
acid being secreted or formed at the root would
indicate that an electro-positive element must have
appeared somewhere, and why not, it may be asked,
might it not have been absorbed by the plant?
Might not those instances in which I obtained no
effect upon the needle arise from the two currents
being so equally balanced, that the resulting effect
-upon the needle was null? In judging of the effect
obtained by the needle’, it appears to me that very
erroneous conclusions would be arrived at, if the
greatest amount of effect were to decide in each
case; we must take into consideration the assumed
origin of the current, and see whether the effect
bears any proportion to the amount of force in

t There is also something to be observed in the motion of the
needle, which can only be obtained by practice, when judging of
slight effects. Far more correct results are indicated when the
needle moves steadily and in a constant and definite manner,
than when a sudden and great amount of motion is obtained.
174 CURRENT ELECTRICITY CHAP. XII. §. 111.

action, and also those circumstances which are likely
to influence the normal result, before drawing our
final conclusions.

From these results we may deduce the following
conclusions :

1st, That when the electrodes of a galvanometer
are brought into contact, one with the external
surface of the spongioles of a plant, and the other
with the sap ascending from the roots, the sap and
the external surface are in opposite electric states:
and, 2dly, That the effects which are observed with
the galvanometer may, in the majority of instances,
be due to ordinary electro-chemical actions, but that,
in some instances, the effect cannot be referred to
these actions, but may be referred to the organic
changes which occur in the fluids in the roots
during vegetation.

Sect. ITI. On the Manifestation of Electric Currents
in the Petals of Flowers during Vegetation.

According to WarrmMann¥, “the currents are
feeble in flowers.”

Circuits were formed between the surfaces of the
petals and the sap from the peduncles, in the follow-
ing plants: Geraniums, various; nasturtium; bal-
sams, single and double; fuchsia; hollyhock; con-
volvulus; vegetable marrow; and cucumber. The
effects obtained were but slight, and in many in-
stances null. Whenever the effects were obtained,

« Loe. cit,
CHAP. XII. §.IV. IN FRUITS AND TUBERS. 175

they indicated the sap to be positive. The greatest
effect appeared with the fuchsia.

It may be a question whether the results were not
due more to the changes which the sap might under-
go from exposure to the air, than to the changes
which might occur in the petal.

Sect. IV. On the Manifestation of Electric Currents
in Fruits and Tubers. ;

BecquEREL*, Donne’, and WarTMANN?, have shewn,
that when the electrodes are inserted into different
parts of a fruit or tuber, effects upon the needle
occur, amounting to 15° or 80° or more, depending
upon the parts in which they are inserted and the
kind of fruit. In some tubers, such as the potato,
the beet-root, and in the carrot, the external layers
were positive to the internal. In the Trope@olum
tuberosum and the Ullucus tuberosus, the effects were
inverse.

Some experiments were made upon the vegetable
marrow and cucumber whilst attached to the plant.
The electrode in contact with the external surface
was slightly positive to the other when inserted into
the centre. Similar experiments were made upon
the apple, pear, and plum, when attached to the tree,
or fresh gathered, or some time after they had been
gathered. The greatest effect appeared with some

~ In his second Memoir.
Y Traité de l’Electricité, tom. iv. p. 164.
z Loc. cit.
176 CURRENT ELECTRICITY CHAP. XII. §. rv.

of the apples, depending, however, upon the parts in
which the electrodes were placed. No definite effects
could be obtained; and as the effects might be re-
ferred to secondary actions, I do not think it neces-
sary to particularize the results. BEcqueREx’, in
speaking of some similar results obtained by Donnz,
adds: ‘“‘ Les courants ne doivent pas étre attribués
a la présence d’un acide et d’un alcali, mais bien
a Vhétérogénéité des parties constituantes des fruits.”

In the potato, carrot, and beet-root, similar effects
to those observed by Becquzret were obtained. In
radishes the external surface was positive to the centre.

The following general conclusions may be de-
duced from the foregoing experiments :

Ist, That when the electrodes of a galvanometer
are brought into contact, one with the surface of the
leaf, and the. other with the sap flowing from the
same leaf, an effect occurs upon the needle indicating
the surface and the sap to be in opposite electric
states. These effects cannot be referred entirely to
ordinary electro-chemical actions, but may be re-
ferred, in part, to the organic changes which take
place in the leaf during vegetation.

2nd, When the electrodes are brought into contact,
one with the external surface of the spongioles of
a plant, and the other with the sap ascending from
the root, the sap and the external surface are in
opposite electric states. The effects which are here

" Traité de l’Electricité, tom. iv. p. 164.
OHAP, XII. §. Iv. IN FRUITS AND TUBERS. 177

observed with the galvanometer may, in the majority
of instances, be due to ordinary electro-chemical
actions, but in some instances the effect cannot be
referred to these actions, but may be referred to the
organic changes which occur in the roots during
vegetation.

3d, That with the petals of flowers slight currents
were obtained; and,

Ath, In fruits and tubers powerful currents may be
occasionally obtained, but these effects are evidently
secondary results, due to the reaction of the different
vegetable juices upon each other.

N
CHAP. XIII.
CONCLUSION.

I sHatu now briefly recapitulate some of the con-
clusions that have been deduced from the experi-
ments and reasonings detailed in the previous
chapters. Sufficient evidence I think has been brought
forward, shewing, that the actions which take place
in the living body, in plants as well as in animals,
viz. secretion, absorption, and nutrition, by whatever
term they are designated, whether vital or organic,
are accompanied with the manifestation of current
force, and therefore present the marked characteristics
of polarity; and consequently, the force associated
with these actions, whether it be called organic-force,
or cell-force, or germ-force, or by any other term,
must of necessity be a potaR force. It will be as well
perhaps to avoid using the term vital force in these
discussions, inasmuch as it is too general in its
application, embracing as it does the whole class
of vital phenomena, including those connected
with the mind. But to the term organic I see
no objection.

The class of actions which present the greatest
resemblance to those which take place in the animal
body, as well as in plants, are undoubtedly those of
CHAP. XIII. CONCLUSION. 179

osmose; the similarity is too great to be overlooked.
Secretion and nutrition may be considered as instances
of organic exosmose, whilst absorption (lacteal and
lymphatic) may be considered as cases of organic
endosmose; the prefix organic will serve to mark
sufficiently their differential characters. My object,
however, is not to enter so much into a minute
comparison of all these actions, as to point out their
general characters, and more especially their marked
characteristics ; to shew, in short, that they are polar
phenomena; and I shall now proceed to detail some
of the consequential results which may be deduced
from these investigations. And, First, in regard to
The Blood. We find that during secretion and
nutrition the blood is in an opposite electrical state
to that of the secreted product, as well as to that of
the muscular or nervous tissue; it is in a positive
state, and this electrical condition is produced and
maintained by these actions. We find no difference
between the arterial and venous blood in regard to
their electrical properties, they both present the
same positive state. Possessing this peculiar elec-
trical character, there can be no doubt that a great
many of the phenomena associated with the blood,
and manifested during its circulation in the animal
body, and which have been termed vital, are referable
to this electrical condition. A further knowledge of
this electrical state of the blood is requisite both to
the physiologist as well as to the pathologist.
Secondly. In regard to the secretions and the
180 CONCLUSION. CHAP. XII.

tissues. From the experiments of Vassat1 Hanvt it
would appear, that the secreted products retain their
peculiar electric state (the negative) when separated
from the body. I have no experiments of my own
either to prove or disprove this supposition. But with
regard to the tissues, the muscular and the nervous,
there can be no doubt that they do retain their pecu-
liar electrical state, which is also negative, like that of
a secreted product. Now this electrical state of the
tissue would appear to be intimately connected with
its vital condition; that the so-called irritability of the
muscular tissue, as well as the so-called sensibility of
the nervous tissue, are most probably entirely de-
pendent upon it.

With respect to the muscular tissue, it would also
appear as a necessary consequence of its electrical
state, that the particles or substance of the tissue
must be in a state of self-repulsion, in a polarized
state or eondition, a charged state, a state of ten-
sion, and that relaxation of the muscular fibre would
be synonymous with this state of tension. Whatever
would interfere with this electrical state would
necessarily diminish this self-repellent action, and
cause an approximation of the particles, in other
words, a shortening of the fibre, and hence would
arise muscular contraction. Now in favour of this
supposition, and presenting a strong argument in
confirmation of this view of muscular contraction, we
are enabled to shew, that during muscular contraction
electricity is evolved.
OHAP, XIII. CONCLUSION. 181

In regard to the nervous tissue, this can also
be shewn to possess the same electrical characters
as the muscular tissue; and this fact shews that
they are evidently due to one and the same cause,
viz. nutrition. Whatever remarks have been made
in regard to the muscular tissue, may also be
applied to the nervous tissue respecting its electrical
condition; but I have not been enabled to satisfy
my mind that any electric force is evolved in the
nerve during nerve action, as is the case with the
muscles during muscular contraction. Du Bors
Rerymonp, however, states, that he has been enabled,
under certain conditions, to obtain an increase as
well as a decrease of the so-called nerve current. My
experiments, on the other hand, shew a decrease, but
no increase. The supposition that nerve force is
similar to current force, is certainly not borne out by
my own investigations; at the same time there is
every reason for considering it as a polar force, from
its intimate connection which may be shewn 1o exist
with other forms of polar force, as in the electric
fish, for example. The questions which physiologists
will have to decide appear to me to be reduced
to the two following: 1st, Is the electric condition
of the nerve merely a condition necessary for
the manifestation of nerve action? or, 2ndly, Is the
electric force converted as it were into nerve force
during nerve action? Now if the decrease in the
nerve current, which I have observed to take place
under these circumstances, be due to a loss of the
182 CONCLUSION. CHAP. XIII.

electric force, and not to a disorganization of the
tissue which I have supposed it to be, then we get
evidence of the conversion, as it were, of the electric
force into nerve force. We need not expect to have
any great effect upon, or any great loss in, the nerve
current, as an equivalent during this conversion. The
quantity of electricity associated with a grain of
water, and evolved during its decomposition, its
equivalent, when existing in the static form, as in a
charged Leyden jar, equals that of a violent thunder-
storm; and so in regard to nerve force the electricity
manifested as nerve current, a loss only of 8° or 4°
might be equivalent to its conversion into nerve
force, but then I think we have a right to expect,
that the decrease in the nerve current, to whatever
amount it might be, ought to be sudden and
definite.

The same arguments and the same reasons may
be applied to muscular action; the loss which
occurs in the muscular current during muscular
contraction may be accounted for, by the electricity
becoming free; and there is also a developement of
heat manifested at the same time; but in the nerves
there is no manifestation of any electricity becoming
free. The questions may arise, whether in the
action of nerve force upon muscular force it is the
conversion of nerve force into electric force that
becomes manifested, or whether it is the electric
_ force of the muscular tissue that is evolved. And in
regard to the fish, the same question may be put,
CHAP. XIII. CONCLUSION. 183

does the electric force exist as such in the organ,
and is merely evolved under the influence of the
will, or is nerve force converted during this action
into electric force? Now with regard to the first
question, I believe that it is the electricity of the
muscular tissue that is evolved, for we can prove
that the muscle possesses a previous electric state.
But with regard to the fish, I am not aware that the
substance of that organ has been proved to possess
a similar electric condition. The muscular tissue
possessing an electric condition, would go far to
prove that nerve force must bear some intimate
relation and connection with the electric force to
cause its manifestation. In all these discussions,
however, it is important to bear in mind, that in the
exertion of force, whether muscular or nervous, there
must be a loss of power, and as they are both
dependent upon nutrition for their manifestation, so
they are dependent upon nutrition for their resto-
ration. Nurrition (including under this head the
kindred actions secretion and absorption) would ap-
pear to be the ultimate and most important act in
organic life.

Dr. Carpenter’, in a valuable Paper On the Mutual
Relations of the Vital and Physical Forces, speaking of
the term ‘ germ force,’ as employed by Mz. Paczr to
designate the power which each germ possesses ‘ to
develope itself into the perfection of an appropriate
specific form,’ adds, “so far from regarding the

2 Philosophical Transactions, 1850, p. 727.
184 CONCLUSION. CHAP. XIII.

whole force which produces the evolution as being
possessed by, or as residing in, the germ, it will be
the author’s object to prove that it is of external
origin.” .... ‘ That the vital force which causes the
primordial cell of the germ first to multiply itself,
and then to develope itself into a complex and
extensive organism, was not either originally locked
up in that single cell, nor was it latent in the
materials which are progressively assimilated by
itself and its descendants; but is directiy and imme-
diately supplied by the Heat which is constantly
operating upon it, and which is transformed into
vital force by its passage through the organized
fabric that manifests it.” Now the influence of
external agencies upon the developement of an
organism is not to be denied; but when we speak
of Heat being converted into vital force, or that -
Light is converted into vital force, that Heat and
Light are absorbed as it were and converted, we
are then considering these forces as entities; not.
that Dr. CarpenreR goes to that extent, for he
speaks of the necessity of a ‘ material substratum ;°
but the language employed leads to this conclusion.
The error arises from the employment of the term
conversion, which expresses inadequately the meaning
that is intended to be conveyed by it. When we
speak of electricity being converted into magnetism
when a current of electricity traverses a helix, the
two forces, magnetism and the current, are produced
and exist at the same time; there is no change of
CHAP. XIII. CONCLUSION. 185

the electric current into magnetism. Conversion
implies a change, a loss on one side and a gain on
the other.

Farapay® commences the ‘ Nineteenth Series of his
Researches’ with stating, ‘I have long held an opinion,
almost amounting to conviction, in common I believe
with many other lovers of natural knowledge, that
the various forms under which the forces of matter
are made manifest have one common origin; or, in
other words, are so directly related and mutually
dependent, that they are convertible, as it were, one
into another, and possess equivalents of power in
their action.” Dr. Carrenrer® observes, “ starting
with the abstract notion of Force, as emanating at
once from the Divine Will, we might say that this
force, operating through inorganic matter, manifests
itself in electricity, magnetism, light, heat, chemical
affinity, and mechanical motion; but that when
directed through organized structures, it effects the
operations of growth, developement, chemico-vital
transformations, and the like; and is further meta-
morphosed, through the instrumentality of the
structures thus generated, into nervous agency
and muscular power.” It appears to me, that we
should be justified in considering this Force which
Dr. Carpenter speaks of to be Porarn Forcr, and
that the different forms under which the various
forces are made manifest, as electricity, magnetism,

» Experimental Researches, vol. iii. p. 1.

© Loe. cit.

oO
186 CONCLUSION. CHAP. XIII.

heat, light, &. are merely different manifestations
of this one Polar Force, and therefore have a common
origin. One great object experimentalists have to
determine is the polar character of the phenomena,
and to point out the connecting links which bind
these different phenomena together.

From the facts recorded in the present Essay, we
can come to no other conclusion than that the force
manifested as organic force in organized beings is a
polar force. The influences which these external
forces, Heat and Light, have over organic develope-
ment is not so direct as would at first sight appear ;
their influence is not to be doubted, but they appear
to be excited in inducing changes of a chemical
nature. Heat and Light without moisture and food
would have no influence over organic actions; and
it is questionable whether there is any loss of heat
or of light indicating a conversion as it were of those
forces into organic force during the developement
of the organism. The connection, the relation that
exists between organic forces and physical forces is
manifested by the polar character of the phenomena,
by the manifestation of current force during organic
actions; and perhaps it would be more correct to
say, that the chemical force of inorganic bodies is
converted during nutrition and. absorption of food
into organic force; and, consequently, the same
influences may be expected to be exerted by Heat
and by Light over organic actions, as are exerted
over ordinary chemical actions.
CHAP. XIII. CONOLUSION. 187

There is one cireumstance which has appeared to
me deserving the attention of physiologists, and one
that has generally been overlooked; I allude to the
influence of magnetism over organic bodies. Living
as we do in a constant field of magnetic force, and
subject as all bodies are to the influence of terrestrial
magnetism, there can be no doubt but that mag-
netism must exert some influence over organic
actions. ‘When we remember,” says Farapay® in
1845, “that magnetic curves of a certain amount
of force, and universal in their presence, are passing
through these matters, and keeping them constantly
in that state of tension, and therefore of action,
which I hope successfully to have developed, we
cannot doubt but that some great purpose of utility
to the system, and to us its inhabitants, is thereby
fulfilled, which now we shall have the pleasure of
searching out.” I have related elsewhere® some
experiments on the Influence of Magnetism over
Chemical Action, which were undertaken as a pre-
liminary step to an inquiry into the influence of
Magnetism over Vegetation; but the means at my
disposal were totally inadequate to carry on the
requisite investigation, and I was consequently com-
pelled very reluctantly to abandon it. The inquiry
may be considered by some as frivolous and useless,
but to me it appears to be one deserving of con-
sideration.

4 Experimental Researches, vol. iii. p, 79.
e Edinburgh New Philosophical Journal, April, July, 1857.
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