224 Mr, cavendish on the Torpedo. 
which the electrical organ is compofed, is divided into a 
great number of partitions by line membranes, the thick- 
nefs of each partition being about the 150th part of an 
inch ; but the thicknefs of the membranes which form 
them is, as he informs me, much lets. The bulk of the 
two organs together in a fifh 1 0} inches broad, that is of 
the fame lize as the artificial torpedos, feems to be about 
24]- cubic inches; and therefore the fum of the areas of 
all the partitions is about 3700 fquare inches. Now 
3700 fquare inches of coated glafs of an inch thick 
will receive as much electricity as 30500 fquare inches 
,055 of an inch thick Ov'; that is, 305 times as much as 
as the plate of crown glafs mentioned in p. 206, or 
about 2| times as much as my battery, fuppofing both 
to be electrified by the fame conductor; and if the glafs 
is five times as thin, which perhaps is not thinner than 
the membranes which form the partitions, it will con- 
tain five times as much electricity, or near fourteen times 
as my battery. 
It was found, both by Dr. williamson and by a com- 
mittee appointed by the Philofophical Society of Penfyl- 
vania, that the Ihock of the Gymnotus would fometimes 
pafs through a chain, though they never perceived any 
light. I therefore took the fame chain which I ufed in 
the foregoing experiments, confuting of 25 links, and 
fufpended it by its extremities from the extreme hooks 
of the machine defcribed in p. 221, and applying the 
end of the machine to the negative fide of the battery, 
(c) Vide Note in p. 206. 
touched 
