134 © Electricity in Machinery. 
ing a galvanic circle together, I was struck with the much higher 
electro-negativeness of charcoal than of copper in relation to zine; 
there being but six substances between zinc and copper, while 
there are eleven between zinc and carbon, which, moreover, 
stands even higher than gold, and next below platina. Besides 
this, its excellent conducting power seemed particularly to qualify 
it to act as an electrometer. Accordingly, I was led to consider 
that it might form an excellent battery with zinc or its amalgam, 
and mentioned the opinion to Prof. Renwick. I was however 
prevented from experimentally demonstrating its powers, until in 
the month of March I perceived in one of the foreign journals a 
short account of a carbon battery which had been successfully 
_ tried in England. I immediately constructed a small battery, 
* consisting of only six pairs of zinc and bituminous coal, and ar- 
ranged as a couronne des tasses. ‘The zinc plates were an inch 
square, consequently there were only six inches of acting zinc 
surface ; the exciting liquid was diluted sulphuric acid. With 
this battery pure water was easily and rapidly decomposed, though 
from not having platina electrodes, and from the want of a vol- 
tameter, the gas collected was not measured. . This experiment 
was witnessed by Mr. Schaeffer, assistant Professor of Chemistry 
in the College. To those who possess batteries of considerable 
power, I would suggest the employment of some form of carbon 
for electrodes in the place of platina. I hope soon to be able to 
present a series of experiments on the relative advantages of cop- 
per and carbon, especially in the case of the constant battery. 
New York, May 9, 1840. 
——— 
Arr. XVII.—Electricity in Machinery ; by Azariau Smrru, Jr. 
Messrs. Editors—Having frequently heard persons employed 
in my father’s manufactory at Manlius, N. Y., speak of the devel- 
opment of electricity by particular parts of the machinery, I was 
led by an article in the American Journal for (July ?) 1839, to the 
examination of the phenomena which furnished me with the fol- 
lowing facts ; which you will please to publish if they add any 
thing. to the light already existing upon this subject. 
=. Sete the machinery referred to, which was con- 
ad h the spinning apparatus, and near the centre of the 
b, ., 
ee, See on 
