448 Mr. Sturgeon on the Ignition of Gunpowder 
jars, which for distinction we will call A and B. I charged 
A positively, and B negatively ; and connected their outsides 
by water. On. exploding A into B, through water, both jars 
became neutralized. A was again charged positively, and af- 
terwards partly discharged through water into B. On dis- 
charging both jars separately, there appeared no difference in 
the explosions. A was once more charged positively, and 
again partly discharged through water into B. On discharging 
B through a moistened thread, gunpowder was ignited in the 
circuit. These experiments were reversed, by charging the 
jar A with negative instead of positive electricity, and the re- 
sults were similar. Hence I concluded, that the ignition of 
gunpowder by the electric fluid depends on the time occupied 
by the latter in passing through it, and not on any change 
in the physical character of the fluid. Hence also, by the 
foregoing experiments (when the intensity of the charge is 
constant), the time occupied by any given quantity of the 
electric fluid, in passing any one point in the circuit, will be 
in some reciprocal proportion* to the thickness of the column 
of water employed in that circuit. 
It was observed in these experiments, that the moistened 
thread soon became nearly dry. Hence the electric fluid had 
either decomposed the water or caused it to evaporate. The 
former effect I suppose to have taken place, which, if true, 
perhaps the decomposition of water by this agent may be 
facilitated by reducing the diameter of the column employed. 
I have not yet had time to ascertain this particular satisfac- 
torily, therefore it remains a mere supposition. 
I have frequently discharged a jar through my own body 
without any other inconvenience than a burning sensation at 
the extremities of the fingers; and have ignited gunpowder in 
the same circuit. : 
So modified is the electrical discharge by being transmitted 
through aqueous conductors, that the effect of an intense 
charge of the most powerful battery may be reduced to almost 
any degree. I have discharged eight feet+ of charged sur- 
face through my own body without feeling the least shock. 
But the burning sensation was very severe. 
In medicine, this modification of electricity can hardly fail 
* This proportion may vary either as the diameter, or as the square of 
the diameter of the column: according as the electric fluid occupies the 
surface, or the whole body of the water; and if the velocity of each in- 
dividual particle of the electric fluid be affected, the transmission of the 
whole mass will also vary on that account. 
+ Eight feet of lining, and eight of coating. 
to 
