THE SPECIFIC HEAT OF BODIES. 565 
and Wheatstone. These methods, however, require 
the use of galvanometers and other delicate in- 
struments, and are not therefore so well adapted 
for my purpose, as the method of determining 
the resistances from the calorific powers, to which 
they are always directly proportional. 
Having now given a rough outline of the new 
method, I may proceed to point out in greater 
detail the course of experiments which may be 
advantageously pursued, in order to apply it to 
the determination of the specific heat of solids, 
liquids, and gases. 
The first business will be to obtain two similar 
platinum wires, each about four inches long, and 
zt> of an inch thick.* It will be desirable to 
employ wires of exactly the same length and 
diameter ; for if perfect equality could be attained 
in the resistances, equation 3 would become 
and the numerical calculations would be much 
simplified. As it is however, extremely difficult, 
* The resistance of the wires ought to be equal to that of 
the battery, in order to produce the maximum calorific effect. 
4F 
