194 
is fufficient for producing movements ina _ 
frog. He accordingly found, that a charge 
of the Leyden phial, forty or fifty times 
lefs than that which gives a fpark hardly 
vifible even m the dark, or fo little as 
even not to move Bennett's electrometer, 
and, inferior by twenty times to that at 
which the moft fenfible electrometer mea- 
fures only one degree, that fuch a charge 
was able to move the feet of a prepared 
frog, which he calls, on that account, an 
animal eleS&trometer. He thinks; that 
electricity a€ts only on the nerves imme- 
diately, and not on the mufcles ; and that 
its firft and principal aétion confifts in 
putting the nervous fluid into -motion, in 
confequence of which, the movements ef 
the mu(cles are produced. He ailows, 
that a ftrong degree of eleétricity is able, 
like any other ftimulus, toact immediately 
on the mufcles ; but not that weak ani- 
mal electricity, which is even impercepti- 
ble by the moft fenfible electrometer. 
It is here that he firft mentions the cu- 
rious experiment with the tongue, already 
noticed by Mr. Sulzer, which is, that on 
coating the point of the tongue with tin-foil, 
and its middle with gold or filver, a fourifh 
tafte will be produced, which is changed 
into a fomewhat alkaline tafte, when we 
change the coating... The author {peaks 
here, likewife, of the greater efficacy of 
the coating with differeut metals. ‘I’he 
mufcles of voluntary motion only are fub- 
jeét to contractions by means of the Gal- 
vanic ftimulus, but neither the ftomach, 
nor the bowels, nor the heart, are affected 
by it, however fenfible they may be. 
In the preface of the German editor of 
Volta’s Writings, fome new difcoveries 
of this gentleman are added from a later 
treatife. He had found, that well-burned 
charcoal, in combination with ametal, may 
be ufed for producing fenfation and muf- 
cular. motion; and he difcovered at the 
fame time that, by means ofthe different 
coatings, the fenfation of light may alfo 
be excited; viz.) by covering the eye-. 
ball with tin-foil, amd taking a piece of 
filver in the mouth, and then bringing 
beth metals in contaét with each other by 
means of metallic points. The fenfation 
of fmell and hearing could not be pro- 
duced in this manner, whence he con- 
cludes, that there probably neither exuts 
an eleétricity peculiar to each organ, nor 
a difturted equilibrium of the electricity 
of the refpcétive organs, but, that there is 
only a great fenfibility of the nerves for 
an el-étricity, otherwife extraneous to 
them, of which they are only fentible in 
the maaner of limple electrometers, 
Hiftorical Statement of Galvanifm. 
electricity, 
[March 1, 
Second Letter of Mr. Vauwt on Animal 
Eleétricity, from the Fournal de Phyfique, 
T. XLI. p. 7z.—Whenever a ligature of 
the nerve was made near its infertion into 
the mufcle, the Galvanic experiment did 
not fucceed ; but when it was fufficiently 
removed from the mutfcle, it immediately 
fhewed itfelf. On applying a conduéting 
arc from the mufcles to the coating of the 
nerve, the contra€tion$ became more vio- 
lent than if it was done the contrary 
way. Galvanifed frogs are fooner liable 
to putrefaction than others. The air, 
in which frogs had been confined, and 
alfo inflammable air, and nitrous-gas, 
caufe no change in their electrical proper- 
ty; azotic-gas, hcwever, feems te dimi- 
nifh ita little. Air corrupted by burn- 
ing fulphur in it, (eems to have a noxious 
effect on animal electricity ; not fo much 
in prepared frogs, as in living frogs that — 
had perifhed in it. Death brought on by ~ 
arfenic or ctcuta (hemlock) has no influ- 
ence on the experiments. He concludes 
with propofing feveral doubts againft Mr. 
Galvani’s theory; and he imagines, that 
electricity might a€t in the body, in the 
fame manner as isfuppofed by phyfiolo- 
gilts of the neryous Auid. 
_ Remarks ou the ‘(fo called) Animal 
Eleciricity, by T. A. C. Gren, in hig 
Journal der Phyfik. Vol. VI. p.-402.—~ 
Mr. Gren thinks the phyfiological conclu. 
fons drawn from the facts hitherto 
known, too premature; and he difap. 
‘proves the appellation of animal eleétri- 
city, as derived from a caufe which is by 
no means afcertained. The ideas which 
Profeflor Reil has Communicated to him 
nya letter here fubjoined are, undoubted- 
ly, worthy of the attention of phyfiologifts..- 
This gentleman imagines, that all the 
phenomena obferved by Galvani and 
Volta might originate in the known irri-~ 
tability of the mufcles, and in the known 
irritating quality of eleétrical matter; and 
that to explain. them, we neéd not have 
recourfe to the opinion of a peculiar elec- 
tricity. For eleétricity is excited (that 
is to fay, the equilibrium of the natural 
electricity is difturbed} by the contaét or 
junéture between the conducting metal 
attached to the mufcle and the coating of 
the nerve, and as the mufcle is probably 
more fenfible of elcétrical matter than of 
other ftimuli, in the manner of a very 
fenfible ele€trometer, the contraétions of 
the mufcular fibre may be derived from 
its known irritability, and from the fenfi- 
bility of the nerves; and may be confider- 
ed as the effect of the known ftinulus of 
which is hete excited. The-- 
action 
