TRANSACTIONS OF THE SECTIONS. 31 
fully charged a battery containing thirty-three square feet of coated surface upwards 
of sixty times in a minute. He also mentioned that by interrupting the electric cur- 
rent and causing it to pass through the thin wire coil of Colladon’s apparatus for induc- 
tive effects, he had obtained a secondary current in the thick wire coil, answering in all 
re$pects to an alternating voltaic current, and sufficient to occasion a permanent though 
slight scintillation of two pieces of steel attached to opposite ends of the wire, and 
rubbed against each other. 
Mr. Armstrong reiterated his conviction that the excitation of electricity in the 
hydro-electric machine was due to the friction sustained by particles of water in pass- 
ing through the escape aperture, for by no other explanation was it possible to account 
for the prodigious influence which is exercised by the form of the escape orifice,—by 
the material against which the current is rubbed,—by the presence of water in the 
issuing steam,—and by the condition of such water with respect to extraneous sub- 
stances contained in it. 
He adverted tu Professor Faraday’s experiment of reversing the electricity of the 
boiler and steam-cloud by introducing oil of turpentine into the steam passages, which 
effect had been attributed by Faraday to the particles of water becoming invested with 
a film of turpentine; but Mr. Armstrong stated that there were many soluble sub- 
stances which were equally effective in reversing the electricity, and so sensitive were 
the electric properties of the water to the influence of foreign substances, that even 
the inappreciable quantity of extraneous matter which the water appeared to acquire 
by contact with condensing pipes of different materials was sufficient to affect the 
excitation of the electricity. 
On the Mechanical Equivalent of Heat. By James P. Joutz. 
The author gave the results of some new experiments, in order to confirm the 
views he had already derived from experiments on the heat evolved by magneto- 
electricity, and from experiments on the changes of temperature produced by the 
condensation and rarefaction of elastic fluids. He exhibited to the Section an ap- 
paratus consisting of a can of peculiar construction filled with water. A sort of paddle- 
wheel was placed in the can, to which motion could be communicated by means of 
weights thrown over two pulleys working in contrary directions. He stated, that the 
force spent in revolving the paddle-wheel produced a certain increment in the tem- 
perature of the water, and hence he drew the conclusion, that when the temperature 
of a lb. of water is increased by one degree of Fahrenheit’s scale, an amount of vis 
viva is communicated to it equal to that acquired by a weight of 890 lbs. after falling 
from an altitude of one foot. 
On Atomic Volumes. By Dr. Lyon Prayrarr. 
Outlines of a Natural System of Organic Chemistry. 
By Grorce Kemp, M.D., F.C.P.S. 
The object of the following paper is to furnish what has hitherto been a desidera- 
tum,—an arrangement of organic bodies with reference to their natural affinities, and 
which, being based on the operations which are observable in living organized bodies, 
will, it is hoped, furnish the student with a means of grouping the results of his la- 
bours, and the philosopher with safe materials for developing those general laws, to 
which every organized being owes its capability of replacing its own ever-wasting 
structure, and reproducing a form analogous to itself. 
Assuming, then, that all organic bodies of which nitrogen forms no part have been 
originally derived from starch, and that those, on the other hand, in which nitrogen 
is an essential element proceed from proteine, we have at once two general classes, 
which we may denominate amylogenic and proteunogenic. 
Class I. Amytocenre Boptes. 
Order 1. Products which result from the direct operation of natural causes. 
Order 2. Bodies produced by the application of artificial agents. 
Order 1. Genus 1, Formula for amylon merely modified by the addition or subtrac- 
