/ 
120 Dr. Hare’s improved Deflagrator. [Aue. 
were placed on a platform beneath them, and being filled with 
water or acid, were raised by levers and a treadle under the 
platform until the plates were immersed. By a series of 250 
pair, barytes was deflagrated, and the platina which supported it 
destroyed like pasteboard before an incandescent iron. Platina 
wire, 3-]6ths of an inch in thickness, was made to flow like 
water. Iron, of like dimensions, burned explosively. - Mercury 
was deflagrated by connecting two vessels containing the metal 
with the poles of the instrument, and then letting a stream run 
from one into the other through a small orifice. 
“Probably the most useful mode of applying such instruments 
to analysis would be to expose substances in carbon to the dis- 
charge in vacuo. I observed that after iron and charcoal were 
ignited between the poles during a few seconds under an 
exhausted receiver, on admitting the air, a flash took place, and 
a yellowish red fume appeared which condensed on the glass. 
It would seem the iron was volatilized, and that the admission of 
air oxidized the vapour.” 
An instrument of this kind produces torture when applied for 
a short time to the back of the hand, and is most sensible over 
any of the most turgid veins, where the skin is tender: there is 
very little difference in the sensation with a charge of water or 
of acid, but the positive pole is most capable of producing pain. 
The shock is not greater in any sensible degree at the moment 
ofimmersion than afterwards. The instrument has the power of 
affecting a very delicate electrometer. A magnetic needle was 
very powerfully disturbed by the deflagrator under all its forms. 
Ina letter from Dr. Silliman to Dr. Hare is then described the 
incompatibility which he had discovered of the voltaic batteries, 
and the instruments of Dr. Hare when used in connexion. The 
instrument used was the deflagrator of 80 coils, and when placed 
in one common recipient or each coil in a separate jar, the 
effects were the same. The deflagrator being connected by its 
proper poles with a galvanic battery of 300 pair four inch plates 
interposed between the two rows of the deflagrator of 40 coils 
each, lost ali its power, and the effect produced was very much 
inferior to that of the battery alone; for in fact the spark was 
hardly perceptible. The chemical powers of the battery were 
also destroyed ; the 300 pairs usually decomposed water, salts, 
&c. with decisive energy, but now hardly produced a bubble of 
gas, or affected dilute infusion of red cabbage. The power of 
giving a shock was also destroyed. When the coils were raised 
out of the fluid and suspended in the air, they acted merely as 
conductors of the power of the common battery only a little 
diminishing it. These experiments were made with different 
combinations from 620 pairs down to-20, and uniformly produced 
an almost entire suspension of the power of both instruments. 
In one experiment, 25 pairs of zinc and copper plates, six 
inches square, connected by slips of copper, and suspended 
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