with the silver ; the groups being separated as before, 
by wire supports. Here there was no effect percep- 
tible, either electrical or chemical. ; 
In the above iments, the cloths which were em- 
loyed to retain the fluid were moistened with water: 
A second set of iments was now performed, in 
which a solution of muriate of soda was employ- 
ed. The pile, whether moistened with water or the 
saline solution, had the same effect upon the electro- 
meters, both as to quality antl quantity ; but when the 
salt was. used, there was a more powerful effect upon 
the sensations, He observed, that a new shock was 
experienced every time either of the hands was brought 
into contact with the 6 aN or removed from it ; 
but that no effect took place as long as they remained 
in contact. When the interrupted circuit was 2 lied 
between the extremities of the pile, the shock might be 
felt, but it was rendered less violent ; and the chemical. 
effects were diminished, but not suspended, while the 
contact of the body was preserved: hence it may be in- 
ferred, that the body is about an equally good conduc- 
tor with water. The retardation of the current a) 
peared to be rather greater in this case, than where 
apparatus was supplied with pure water. 
he pile was now dissected in the same three ways 
as before, muriate of soda in solution being employed 
instead of water. In the first dissection, 7. e. with the 
moistened cloths between the plates, the same electric 
effects were exhibited by the electrometers, the same 
shock was felt, and the same chemical effects were pro- 
duced, only in rather a less di than in the continu. 
ous pile, with muriate of soda. The second and third 
dissections of the pile produced exactly the same effect, 
as when the same dissections were employed with pure 
water. : 
thesis The author afteMwards enters upon a number of spe- 
the diffe- eylations respecting the manner in which the electric 
cause fluid circulates through the apparatus, and upon the 
py ~ immediate cause of the electrical and chemical pheno- 
; mena. He-conceives, that when no cause of retarda- 
tion exists, the electric fluid circulates so rapidly through 
the pile, as not to exhibit any of its effects, or indeed 
not to indicate its presence ; and that when these are 
manifested, it always depends upon some acm 
cause. The electrical and chemical effects are sup 
to originate from different parts of the pile, or from dif- 
ferent groups, considered in their relation to the parts 
contiguous to them. The electrical effects consist sim- 
ply in the combination of the two metals, each pair be- 
ing separated by a non-metallic conductor; while for 
the chemical effects, ternary groups are necessary, the 
two metals with a fluid between them. This distinc- 
tion between the two sets of properties, or the two 
modes of action, is sup to be proved by the dif- 
ferent effects which are produced by the pile in its three 
states of dissection. In the pile dissected in the first 
manner, which indeed may be regarded as equivalent 
‘to the instrument in the continuous state, both the elec- 
trical and chemical action takes place: for here are the 
two metals, either in contact, or connected by the wire 
frames, for the electrical effects; and for the chemical 
effects, there are the two metals with the wet cloth’in- 
terposed. In the pile as dissected in the second man- 
ner, there are the binary groups, i. e. the metals in 
contact, and accordingly they produce the electrical ef- 
fects ; but we have no chemical effects, because they 
have no fluid between them. In the third dissection, 
no effects are produced ; we have not the chemical ef- 
fects, because the metals have not the wet cloth be- 
4 
GALVANISM. 
93 
tween them, and we have no electrical effects, because History. 
the zinc has the copper plate on one side, and the wire “-"Y""” 
frame on the other, which have the same electrical re- 
lation to the zinc, and therefore counteract each other. 
The different effects which seemed to ensue, between Pile of sit- 
the pile when furnished with pure water, and with the ver and 
solution of a neutral salt, induced M. De Luc to éxa- Pewter- 
mine what connexion existed between the oxidation of 
the zine, and the chemical action of the instrument. 
For this purpose he formed a pile of silver and pewter, 
the pewter being selected for the experiment, pudsase 
it has an electrical relation with silver, and is oxidable 
by muriatic acid, at the same time that: it is not much 
affected by pure water. In the first instance, water 
was interposed between the plates; the extremities of 
the pile, as indicated by the electrometer, became elec- 
tric, the pewter side negative, and the silver positive; 
but there was no shock, nor any decomposition of the 
water in the interrupted circuit. A pile was then form- 
ed of such a number of zinc and silver plates, that its 
electrical energy might be the same with the pewter pile ; 
but here there was both the shock produced, and the de- 
composition of water. The pile of pewter and silver was 
then fitted up with muriatic acid; and in this case, when 
the pewter plates became oxidated, the shock and the de- 
composition of water were both produced. From these General 
experiments, the author deduces the following conelu- conclusions. 
sions. ‘When the metal is not oxidated, no chemical 
effect is produced on the water in the interrupted cir- 
cuit. When the oxidation is produced by means of pure 
water, there is no shock, although the chemical effects 
take place ; and lastly, when either of these effects are 
produced, the current of electricity is retarded in its 
e across the water in the interrupted circuit. 
It was in the prosecution of these experiments, while Discovery 
he was examining the effect of different conducting of the elec- 
substances placed between the plates, that M. De Lue ‘tic column. 
was led to the discovery of the curious instrument, cal- 
led the Electric column ; a pile consisting of a number 
of dises of zine and gilt paper, placed alternatel 
each other, and included in a fie tube. This has al. 
ready been described under the article ELecrricrry, p- 
469, and as it must be regarded as a stricly electrical a 
paratus, we shall not enter into any details respecting its 
effects or its mode of action. See Nicholson’s Journal, 
XXvi. 39. 
While Sir H. Davy and M. De Luc were thus enlar- Children’s 
ging our knowledge of the powers of galvanism as a large batte- 
chemical agent, and of the means by which its wonder- ty- 1809. 
ful effects are accomplished, Mr Children was advan- 
tageously employing himself in improving the apparatus. 
He formed a battery, constructed upon a principle, ori- Pratz 
ginally suggested by Volta, according to which the €CLXIII- 
plates are not cemented together, but are connected Fis > 
only at the top by a metallic conductor, and are then 
immersed in the cells of a trough. He employed 20 
pair of plates, of four feet by two, making in all a sur- 
face of 92,160 square inches. The fluid that he used 
was a diluted mixture of nitric and sulphuric acids, the 
whole quantity being no less than 120 gallons. The 
effect of these large plates was to fuse entirely, in 
about 20 seconds, 18 inches of platina wire, of one- 
thirtieth of an inch in diameter, and to render three feet 
of the same wire red hot. Charcoal was burned with 
intense brilliancy. It seemed not a little remarkable, 
considering the powerful effect on platina wires, that 
the action of this battery on iron wires was compara- 
tively trifling. Of iron wire, 1-70th of an inch in 
diameter, it barely fused ten inches, and had not power 
