Manchester Memoirs, Vol. xlviii. (1903), No. JJ. 



III. On a Method of Ice Calorimetry. * 



By H. E. SCHMITZ, M.A., B.Sc. 



Read November jrd. Received December ist, igoj. 

 Introductory. 

 If a body at a temperature below o'-'C. is plunged into 

 water at o'-^C. a coating of ice forms round the body. The 

 mass of the ice is a measure of the quantity of heat 

 absorbed by the body when its temperature rises to 0°C. 

 If it is required to determine the specific heat of the 

 material of which the body is composed, we may apply 

 the following equation : 



f^ -d ^ ^ Mass of ice x Latent heat of water 



Specific heat = — — — = ^ . . , -j — — 



Mass of body x Initial temperature of body 



This method of calorimetry possesses the great 

 advantage of simplicity of principle. This advantage it 

 shares with the method of steam calorimetry so success- 

 fully used by Joly, and also with the converse method of 

 ice calorimetry practised by Black, Wilke and Lavoisier 

 and Laplace, but abandoned by later workers.^ 



We may attempt to determine the mass of ice formed 

 round the cold body in either of two ways. The ice- 

 coated body may be weighed while suspended in the 

 water of the calorimeter, or it may be removed from the 

 water and then weighed. In the first case it is necessary 

 to know the density of the ice formed, and the inclusion of 

 air-bubbles will be fatal to the success of the method. In 

 the second case it is essential that zvater shall not be 

 included within the ice-coating, and water must not be 



* This paper contains a more complete account of experiments of which 

 a summary is given in the Proceedings of the Royal Society, Vol. 72, 

 pp. 187-190. 



t Bunsen's well-known method hardly belongs to the class of methods 

 here considered. 



December joth^ 1903. 



