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calling this heat the production of force, when no mechanical 
force whatever is called into action by those mutations of 
water. They are, however, plainly explained by the agency 
of heat, in its chemical union with water and its evolution 
from water. Although the evolution and absorption of heat 
from the compression and expansion of elastic fluids bears a 
constant relation to the amount of compression and to the 
compressing force, yet this is not the case, as Mr. Rankine 
supposes, in the resistance to compressing forces by liquids 
and solids ; the amount of compression in these latter cases 
depends upon the relative mobility of the particles of the 
bodies, and we find forces of great energy, exerted against 
yielding solids, as in carriage and other springs and elastic 
bodies, are in continuous action without producing any 
sensible heat when no compression takes place. If it were 
true that acting forces always produced their equivalent in 
heat, then the powerful movements of railway springs, 
hydraulic presses, and the like, should raise intense heat 
in the steel springs and water exerting such force, and the 
absence of any heat in such cases, must be fatal to the 
dynamic creation of heat* 
The following Paper, “ On the Chemical Constitution of 
American Rock Oil,” by Mr. Schorlemmer, Assistant in the 
Laboratory of Owens College, was communicated by Professor 
Roscoe : — 
In a Paper published in the October number of the 
Chemical Society’s Journal, I showed that the products of 
the distillation of cannel coal at a low temperature contain a 
series of homologous hydrocarbons of the formula C„ IT,,^* 
I further showed that these are the hydrides of the alkohol 
radicles, as, upon treatment with chlorine, they yielded by 
substitution of one atom of hydrogen by one of chlorine the 
* I have experimentally determined the thermal effects of compressing 
or dilating metals and fluids, and have found these effects to be strictly in 
accordance with the dynamical theory of heat. See Phil. Trans, , 1859. Ed. 
