*64] 
the immediate. exciting cause of 
these motions could not be derived 
from the action of the metals upon 
the muscle and nerve, to which 
they were applied; otherwise it 
must have been admitted, that my 
body anda metal formed together a 
better conductor of the exciting in- 
fluence than a metal alone, the 
contrary of which I had known, 
from many experiments, to be the 
ease. The only source, therefore, 
te which it could possibly be re- 
ferred, was the action of the metals 
upon my own body. It then oc- 
curred to me that a prqper oppor- 
tunity now offered itself of deter- 
mining, whether animals contribute 
to the production of this influence 
by means of any other property 
than their moisture. With this 
view, I employed various moist sub- 
stances, in which there could be no 
Suspicion of life, to constitute, with 
one or more metals, different from 
that of the coatings of the muscle 
and nerve, a connecting medium 
between those coatings, and found 
that they produced the same effect 
as my body. A single drop of 
water was even sufficient for this. 
purpose ; though, in general, the 
greater the quantity of the moisture 
which was used, the more readily 
and powerfully were contractions of 
the muscle excited. But, if the 
mutual operation of metals and 
moisture be fully adequate to the 
excitement of an influence capable 
of occasioning muscles to contract, 
it follows, as an immediate conse- 
quence, that animals act by their 
moisture alone in giving origin to 
the same influence in Mr. Galvani’s 
experiments, unless we are to admit 
more causes of an effect than what 
are sufficientfor its production. 
Before I dismiss this part of my 
ANNUAL REGISTER, 
1795. 
subject I may mention, that, being 
in possession of a method to deter- 
mine what substances are ‘capable, 
along with metals, of exciting the 
influence, I made several ex peri- 
ments for the purpose of ascertaining 
this point. I found, in consequence, 
that all fluid bodies, except mer- 
cury, that are good conductors of 
electricity, all those at least which 
I tried, can with the did of metals 
produce it. The bodies I tried, be- 
sides water, were alcohol, vinegar, 
and the mineral acids; the last 
both in their concentrated states, 
and when diluted with various pore 
tions of water. Alcohol, however, 
operated feebly. On the other . 
hand, no fluid, which is a non 
conductor of electricity, would assist 
in its production : those upon which 
the experiment was made were the 
fat and essential oils. " Ether, from 
its similiarity to alcohol, I expected 
would also have concurred in the 
excitement of the influence, but it 
did not; neither would it conduct 
the influence when excited by any 
other means. I may remark, how. 
ever, that the ether I employed 
had been prepared with great care : 
other ether, therefore, less accurate- 
ly made, may possibly be found to 
contribute to the excitement of the 
influence, either from the unde= 
composed alcohol, or naked acid, it 
may eontain. 
Having thus given an answer to 
the first question, I proceed to the 
discussion of the second, 
It has hitherto been maintained 
by every author, whose works | 
have read upon the subject of Mr. 
Galvani’s experimenis, and by 
every person with whom I have con- 
versed respecting it, that metals are 
the only substances capable, by their 
application to parts of animals, 
‘ of 
