Mr. Kemp’s Experiments on Galvanism: ep: 
When liquid copper was used, and an iron plate substituted for 
the copper plate used in the former experiments, the effect on the 
needle was also rather powerful. é 
On increasing the temperature to a much greater extent, and 
using liquid cast iron, anda wrought iron plate, with fused flint 
glass for a liquid to excite the metals, the needle was also affected, 
which showed that galvanic electricity was generated, and even 
conducted, at this high temperature, by substances which, in their 
solid state, were totally incapable of transmitting electricity, al- 
though of a very high intensity. 
In the preceding experiments, the developement of electricity 
was evidently caused by a portion of the oxygen existing in the 
salts combining with the most oxidizable metal, and thereby pro- 
ducing a current of electricity in the same manner, and in the same 
direction, as that which takes place when liquids are used to excite 
metals at ordinary temperatures. But that solid substances, which 
are not conductors of electricity, such as giass, should be made to 
conduct it, merely by being liquified, seems to be totally unac- - 
counted for. ier 
According to the theory generally received in this country -on 
the subject, galvanism can only be excited by a liquid compound 
substance, consisting of two ingredients, which, of course, must 
be in opposite electric states ; and that, when this liquid is brought 
‘in contact with the metallic plates, the oxygen or negative ingre- 
dient combines with the positive plate, and the hydrogen or positive 
ingredient is attracted to the negative plate. In this manner it is 
supposed that the equilibrium is restored which had been de- 
stroyed by the contact of the metallic plates. 
In consequence of the success of the preceding experiments, I 
was induced to employ substances still less likely to excite electri- 
city, being both simple and non-conductors of electricity. : 
_ The same crucible that was used in the preceding experiments 
was filled with lead as formerly ; and, when it had arrived at a red 
heat, the remainder was filled with liquid sulphur. The copper 
plate was heated to redness, and brought in contact with the sul- 
phur ; the wire coming from the bottom of the crucible, and that 
from the copper wire, were, as formerly, connected with a needle 
apparatus. When the circuit was completed, the needle was very 
powerfully affected ; while the sulphur combined rapidly with the 
copper plate. From the heat of the metals, the sulphur, at the 
same time, underwent combustion, and consequently formed sul- 
_ phurous acid gas. 
The crucible and lead being prepared, as in the last experiment, 
the copper plate was also placed in the crucible. It was then co- 
vered over with fire-clay, through which two porcelain tubes passed 
to open into the cavity remaining in the crucible between the melt- 
ed lead and copper plate. When the crucible had arrived at a red 
heat, the liquid sulphur was poured through one of the tubes; 
and as soon as it came in contact with the metals, so as to produce 
VOL. I. 2A 
