﻿182 Prof. R. Bunsen's Calorimetric Researches. 



units of heat. Let I represent the latent heat of liquidity of 

 water, then 



o-ives the weight in grammes of the melted ice which correspon ds 

 to one division of the scale. The equation for I is therefore as 

 follows : 



7 $w S e V 



~~ W w s e s w v' 

 or, according to equation (2), 



1= X 



By substituting the values found above, 

 ;?= 000085257, 

 W w = 14-660, 

 W„,= 14654; 



in the equation, therefore, we get for the latent heat of liquidity 

 of water 7, 



80-01 



80-04 



Mean . . 80*025 



The value found by other experimenters by the method of 

 mixture is 



According to Regnault . 79*4 

 „ Person ♦ . 80*0 



„ Hess . . . 80-3 



It will be possible to determine the heat of combustion of 

 gases by the ice-calorimeter with much greater accuracy than 

 could be done by the method hitherto available. It follows, by 

 equation (4), from the heat of combustion of hydrogen, that 10 

 cubic centims. of this gas at 0° C. and 760 millims. pressure 

 would produce by its combustion with oxygen an indication of 

 453 divisions of the scale in the calorimeter of the instrument de- 

 scribed. It suffices, therefore, to burn very small quantities of 

 gases (easily prepared pure when so little is required), and to 

 measure the difference produced on the scale, in order to obtain 

 directly the heat of combustion in thermal units, without intro- 

 ducing any of the very uncertain corrections hitherto unavoidable. 



