On the Generation of Statical Electricity. 99 
cylinder of 10 inches diameter and 15 inches long; and lastly a 
large and beautiful instrument of 38 inches plate, manufactured 
in Paris. 'To measure accurately the quantity of electricity in 
each case, one of those admirable galvanometers of 3000 turns 
of wire, constructed by M. Goujon of the Polytechnic School, 
Paris, was employed ; the amalgam of the rubbers being connect- 
ed, by means of a copper wire, with one extremity of the coil, 
the other extremity communicating with the prime conductor, by 
means of a glass tube containing water, having a wire inserted 
in eachend. The maximum permanent deflection of the needle 
by the 12 inch plate was 16°. 
Having thus attained, satisfactorily, the two objects proposed, 
the discussion will be taken up on the questions first suggested, 
viz. is statical BRE cn ‘apne by friction, by chemical action, 
or by friction and chemical action? The solution of the first 
two solves the third. To this branch of the subject, it was not 
considered necessary to devote much attention; for the results 
obtained by others, superior to the writer in abilities, have decided 
quite conclusively, that chemical action does not produce the ex- 
citement of the electrical machine. Indeed it is difficult to con- 
ceive, how ordinary chemical action in the amalgam of the rub- 
bers, can influence the generation of electricity, except in the single 
case previously mentioned. For if it be supposed, that the sur- 
face of the amalgam is made up of numerous small galvanic cir- 
cles, as is doubtless the case, the air acting, possibly in conjunc- 
tion with its watery vapor, as the exciting medium ; no action 
could be produced, unless such circles, either singly or collective- 
ly, were closed. Under the improbable supposition, that parts of 
the glass acted as conductors to complete such circles, it would 
be contrary to all analogy to suppose, that in their movement, 
they carry off a portion of such current. Neither can it be sup- 
posed, that it acts by inductive influence; as in such case, the 
induced electricity would be of a tension, so extremely low, as 
not to be apppreciable 
In order, nevertheless, to satisfy any existing doubt, a tube 
electrical machine was constructed,* whose piston iirfovetiod the 
part of a rubber; and the apparatus arranged, so as to admit of 
being filled with different gases. It was thus found that air, oxy- 
* American Journal of Science and Arts, Vol. xxv1, page 111. » 
