370 Modification of Ampére’s Rotating Galvanic Element. 
Art. Xi.—Modification of Ampére’s Rotating Galvanic Ele- 
ment; by 'T. Epmonpson, M. D. Baltimore. 
Te instrument is constructed in such a manner, that, the current 
of galvanism proceeding from the zinc side of the small element, 
will pass through a helix arranged as an electro-magnet, as it circu- 
lates onward to the copper side of the element. 
a, the zine cylinder in 
section,—O, the double cop- 
per cell,—c, the electro- 
magnet, made, simply by 
wrapping a coated copper 
wire around a tube of the 
common tinned iron,—d, a 
small metallic cup contain- 
ing a globule of quicksilver, 
into which is dipped one 
end of the helix,—e, a small 
agate center, intended for a 
non-conductor,—f, a metal- 
lic cup, also containing a 
globule of quicksilver, into 
which is dipped the other 
end of the helix. 
Upon exciting this small 
element with an acid solu- 
tion, the current of galvan- 
ism prevented from passing 
directly from the zinc to the 
copper, on account of the 
non-conductor at e, is obli- 
ged to traverse f, and circu- 
late through the helix to d, 
before it can reach the cop- 
per side of the galvanic ar- 
rangement. 
The instrument has fre- 
quently revolved two hun- 
dred times in a minute, the /=== 
1 moving fast in 
one direction, and the zinc | ill 
cylinder in the opposite di- 
rection with great rapidtiy. 
il 
a 
SEA RITIT 
