THE SPECIFIC HEAT OF BODIES. 561 
tures, appear to be founded upon correct theo- 
retical principles. Both of them are, however, 
exposed to several sources of error which the 
utmost skill and ingenuity has not hitherto been 
able to remove. In proof of this I may mention 
that V. Regnault, one of the most expert experi- 
menters in this department of physics, has found 
that the two methods give different results when 
applied to the determination of the capacity of the 
same body. It is sufficiently obvious, therefore, 
that although the processes hitherto used are, in 
skilful hands, capable of giving rough approxima- 
tions to the truth, they are at the same time 
wholly unfitted for the determination of specific 
heat with that extreme degree of accuracy which 
is so desirable in the present state of science. It 
will not therefore, I hope, be deemed superfluous 
to point out a new, and, as I confidently believe, 
far better method, founded upon those laws of the 
evolution of heat by voltaic electricity which I 
have developed in previous memoirs. 
I propose in the first place, to point out briefly 
the principles of the new method, and then to 
show how it may be applied, in order to determine 
the specific heat of solids, liquids, and gases. 
