43S 
ELECTRICITY. 
table that they originate from the fame fource. With 
regard to the latter, its power is now known to depend 
on oxydation ; fo alfo does the excitement in the former 
appear very much to depend on the fame procefs. 
9. I have found that, by ufing an amalgam of filver-, 
or of platina, which are not liable to .be oxydated, I 
could obtain no eledtricity. An amalgam of tin, on the 
contrary, affords a good degree of excitement. Zinc adts 
fti 11 better; but the beft amalgam is made with both tiit 
and zinc, a mixture which is more eafily oxydated than 
either metal feparately. 
10. But, as a further trial whether oxydation affifts 
in the production of eledtricity, I mounted a fmall cylin¬ 
der, with its cufhion and conductor, in a veflel fo con¬ 
trived that I could at pleafure change the contained air. 
After trying the degree of excitement in common air, I 
fubftituted carbonic gas,.and found that the excitement 
was immediately deftroyed, but that it returned upon re- 
admidion of atmofpheric air. In conformity to this hy- 
pothefis, we find that the metal oxydated is, in each cafe, 
in a fimilar (late of eledtricity ; for the cufhion of the ma¬ 
chine, by oxydation of the amalgam adhering to it, be¬ 
comes negative ; and, in the fame manner, zinc oxydated 
by the accumulated power of an eledtric pile, or fnnply 
by adtion of an acid, is alfo negative. This fimilarity in 
the means by which eledtricity and galvanifm appear to 
be excited, in addition to the refemblance that has been 
traced between their effedts, thews that they are both 
elfentially the fame, and confirms an opinion that lias 
already been advanced by others, that all the differences 
difcoverable in the effedts of the latter, may be owing 
to its being lefs intenfe, but produced in much larger 
quantity.” 
While thefe refearches were going on in England, fi- 
jnilar experiments were made by profeffor Van Marum 
at Haerlem, by help of the grand Teylerian machine. 
This able eledtrician afferts, that relatively to the com- 
jiarifon of the fenfations, or (hocks, communicated by 
the difeharge of a battery, charged to different degrees 
of tenfion, by the contadts of the conductor of the elec¬ 
trical machine, with thofe of charges of the fame tenfion 
bv means of the pile, he was convinced, by repeated ex¬ 
periments, that there is no perceptible difference in the' 
/hocks communicated by the difeharges of the battery, 
whether charged by t.he machine, or by the pfle, pro¬ 
vided the tendons of the charge are equal. He flatters 
liimfelf that he has proved, in the mo ft decifive manner, 
by experiments -on a large fcale, the identity of the cur¬ 
rent of the fluid put in motion by the Voltaic pile, and 
of that to which an impulfion is given by an electrical 
machine. The identity ot the currents of each apparatus 
having been thus clearly eflablifhed, and placed beyond 
any doubt, it follows as a diredt confequence of all the 
above-cited experiments, that there can no longer be any 
pretence for the adtion of a particular fluids which had been 
Inconliderately fuppofed to refide in the Voltaic column. 
Thefe experiments, added to thofe made by profefl'or 
Volta himfelf, prove that the adtion of the above co¬ 
lumn, or pile, produced by the contadt of two metals 
which touch each other, can be no other than an eleCtri- 
c.al effedt. As the refults they furnifli are conftantly ex¬ 
plained by the adtion of two diverl'e metals, or of two 
different fubftances which are employed, the fuppofition 
of a particular fluid is entirely done away ; and, confe- 
quently, the true denomination of the Voltaic pile, ought 
in future to be called eledtric, and not galvanic. 
The general opinion relative to animal eledtricity, 
which the naturalifts of Italy, Great Britain, Germany, 
and France, formed after repeating the experiments of 
Galyani, was, that the metallic influence is not imparted 
5 o the mufcles, until after it has been communicated to 
the nerves. This concluflon appears to have been dic¬ 
tated by the effedts to which the nervous parts, as well 
as the organs of the fenfations, are fubjetted in galvanic 
experiments. It receives an additional fupport from the 
afl'urance given by Humboldt, that it is impoflible b* 
produce the contradtions, in a portion of the middle prei 
pared in fuch away as to divert: it entirely of every ner¬ 
vous ramification. It is, notwithrtanding, certain, that 
the coatings of the mufcles alone have been fometimes 
efficacious in the produdtion of the galvanic effedt; and 
this would be an inconteftible proof of an irritation inde¬ 
pendent of the nerves, if it were not likewife certain, 
that this irritation is capable of penetrating into the in¬ 
ternal tilfue of the organs, in which the nerves are con¬ 
cealed. It would, however, be too rarti to circumfcribe 
to the nervous and fenfible fibres, the imprefiion of the 
metallic ftimulus, feeing that, independently of feveral 
rational arguments which prove the contrary of this affer- 
tion, experiments have demonftrated that the adtion of 
galvanifm is directed both to the vafcular and nervous 
fy (terns. 
Several galvanic exp riments and obfervations have 
been recently publifhed by M. Bichat, phyrtcian to the 
Hotel Dieu in Paris, and author of a celebrated work on 
anatomy. In fpeaking of the influence of the dertrudtion 
of the brain on that of the heart, after having proved, 
conformably to obfervation and experience, that it is not 
immediately by the interruption of the cerebral adtion 
that the heart ceafes to adt, he confirms this fundamental 
datum of phyfiology and pathology, by a feries of galvanic 
experiments, which demonrtrate that the heart is in all 
cales independent of the brain. 
“ Thefe experiments,” he obferves, “ were made with 
the moft fcrupulous attention, becaufe feveral very re- 
fpedtable authors have advanced a contrary opinion, 
and have endeavoured to prove that the heart, together 
with the other mufcles of organic life, do not differ, as 
to their fufeeptibility to the galvanic influence, from the 
different mufcles of animal life. I (ball therefore detail' 
the obfervations I have made on animals with red and 
cold blood. 
“ 1. In feveral experiments made on frogs, I coated 
the brain, on the one hand, with lead, and the heart and 
mufcles of the inferior extremities, on the other, with a 
long lamina of zinc, the upper end of which touched the 
heart, and the lower end the mufcles. Having, by the 
means of filver, eftablilhed a communication between the 
coatings of the mufcles and thofe of the brain, the move¬ 
ments of the limbs conftantly followed ; but I could not 
perceive any acceleration in the contractions of the heart* 
when it ftili continued to beat ; and when its aCtion had 
entirely ceafed, it did not difplay the fmalleft movement. 
Whichever may be the voluntary muffle that is coated 
at the fame time with the heart, with a view to a com¬ 
panion of the phenomena they exhibit at the moment of 
the metallic communication, there is conftantly a marked 
and decided difference. 
“ 2. In the cafe of other frogs, I coated, with a com¬ 
mon metallic wire, on the one hand, the cervical part of 
the fpinal marrow, in the upper region of the heart, to 
the end that the coating might be above the part where 
the nerves which proceed from the great intercoftal nerve, 
and thence to the heart, originate ; and, on the other 
hand, the heart, and any one of the voluntary muffles. 
I conftantly noticed a refult fimilar to the one which at¬ 
tended the preceding experiment, whenever the commu¬ 
nication was eflablifhed. There were invariably violent 
agitations in the voluntary mufcles, without any vifible 
alteration in the contractile movements of the heart. 
“ 3. I endeavoured to denudate the nerves which 
lead to the heart of frogs. Several greyifh filaments, 
fcarcely perceptible, with the nature of which, I muff 
acknowledge, I am not fully acquainted, were coated 
with a metallic fubftance, at the fame time that the heart 
was made to reft on a fubftance of a fimilar nature. When 
the communication was eflablifhed by means of a third 
metal, not the fmalleft fenfible efteCt was to be perceived. 
It appears to me that thefe trials, which had been partly 
made before I engaged in them* are well calculated to 
1 decide. 
