428 
Diff. Infugur. Med. de Ele@tricitate fic diéta 
Animali, Auét. Chrift. Henr. Pfaff. Stutt- 
gardt, 1793, p. 85-83 tranflated into 
German in Gren’s Journal d. Phyfik, 
vol, vill. p. 196.—Fortgefetzte Bemerkun- 
gen uber die Thierifche Eletricitat; i.e. 
FurtherObfervations on Anima! Ele@tricity, 
by Ch. H. Pfaff, ibid. p. 272, p. 280; 
Pp: 377-—Pfaft’s Nachtrag zu feiner Difler- 
tation ; i.e. Appendix (or additional Re- 
marks) to his Diflertation. In Harten- 
kiel’s Medicinifch-chirurgifche Zeitung ; 
3. e. Medical and Surgical Gazette; Year 
1794, vol. il. p. 185—192.—Ueber Thie- 
rifche Ele€tricitat und Reitzbarkeit, &c. 
i.e. on Animal Ele€tricity and Irritability. 
A Contribution to the lateft Difcoveries 
on thefe Subjeéts, by Dr. Chr. H. Pfaff. 
Leipzig, 1795, p. 398—8vo. for Coufius. 
Of thefe interefting publications on 
animal eleétricity, we fhall only give an 
Account of the laft mentioned, the former 
being merely prefatory to this very inge- 
nious work. © 
In the Introduction, the author ex- 
prefles himfelf in the following manner, 
concerning the name, Azimal Eledtricity : 
—* Alihough I do not mean to decide 
the identity of animal electricity or its 
real exiftence in nature, I have ufed this 
exprefiion for that ftimulus lately difcover- 
ed by Galvani, as it is generally adopt- 
‘ed, and underftood to characterife a pecu- 
liar ftimulus, and as it feems different 
from all others hitherto known.’” ‘The 
author firft relates all the Galvanic phe- 
nomena, which he has repeated, multipli- 
ed, and more accurately determined; but 
we fhall give here only a curfory and ge- 
neral account, as we purpofe to prefent 
our readers with a more accurate furvey 
of all the tranfaétions, as far as they 
were then advanced, when we fhall after- 
wards announce a work of Mr. Humboldt, 
which is of a later date. After having 
recited in the firft fection the experiments 
on exciting convulfions by means of ani- 
mal electricity, viz. by either coating the 
nerves and different bedies which are in 
conneftion with them, or merely the 
mufcles ; he proceeds to communicate the 
experiments made on animals from diffe- 
rent claffes, and on plants, and on invo- 
luntary mufcles, in which he likewife fuc- 
ceeded in exciting convulfions; and he con- 
cludes with relating the experiments on 
the action of mephitic airs, poifons, &c. 
on irritability, as far as its force or de- 
creafe may be determined by the applica- 
tion of animal eleétricity. The third fec- 
tica contains fome additional obfervations 
to the firit feCtion g in the fecond, however, 
_Hiftorical Account of Galvanifm. 
[June I, 
are propofed experiments, made for the 
purpofe of exciting fenfation by means of © 
animal eleétricity. The fourth fection 
has thetitle of General Conclufions, and 
the author treats under this head of the 
conditions and laws which feem to take 
place in the Galvanic phenomena. The 
conditions depend either internally on the 
parts in which the phenomena appear, 
and which the animal elcétricity is to a& 
upon in order to produce thofe changes, 
or elfe the conditions arife from without. 
In the firft cafe we have to attend to the 
nature of thofe parts which are endowed 
with nerves, as organs neceflary for their 
re{pective funétions, and penetrating into 
their very fubftance ; all parts which are 
affected by the Galvanic ftimulus, are pro- 
vided with them, Here the author takes 
an opportunity of examining the hypo- 
thefis of Drs. Behrends and Sommering, ac- 
cording to which the heart is fuppofed to 
be properly without nerves. Amonett 
the external conditions we have to conft- 
der the excitors, viz. the metals, ores, 
charcoal, and plumbago. But, though 
the conduéting quality, and the affinity te 
oxygen, are properties common to thofe 
fubftances, yet their exciting quality never 
keeps pace with thofe properties ; that is 
to fay, an intenfe degree of the two former 
is not always attended with an equally 
intenfe degree of the exciting quality, and 
vice verfa. A third condition confifts 
in the combination of the animal parts 
with the excitors, and of the excitors with 
each other. All thefe conditions.may be 
comprifed under this general law :—** The 
application of two bodies, which are to 
be chofen amongft the beft conductors of 
electricity, to moift parts, and fuch a - 
combination of the two bodies with the 
moift parts, that a free circulation of elec- 
tricity betwixt thofe bodies may be efta- 
blifhed, by means of the beft conduétors, 
and, at the fame time, between thofe 
parts by the nerves belonging to mufcles 
or to organs of fenfe, are requifite for ex- 
citing the phenomena of animal eleétricity. 
Another law, formerly propofed by the 
author, viz. that the force and duration of 
any contraction is in a compound propor- 
tion with the quantity of difference of 
the electrical conducting quality of both 
metals, and with the quantity of the con- 
duéting quality of the metal that is ap- 
plied to the mufcles, obtains here farther 
evidence, and is more fully determined 
than before. Ina fecond part of the fame 
fection, the author propofes feveral ingenious 
ideas concerning the doétrine of irritabi- 
, 
