16 Scientific Proceedings, Royal Dublin Society. 



its temperature, T, as it issues, and afterwards find its weight, W \ 

 note the rise of temperature of the calorimeter from t to 6 ; then 



<? K!z± 



W'T-B' 



A few minutes suffioe to complete the whole determination to 

 within a limit of error of one per cent. It will be obvious that 

 for ascertaining the specific heat of small quantities of rare liquids 

 this form of calorimeter will be found particularly applicable ; and 

 as the determination of the specific heats of organic liquids can 

 thus be readily and accurately made, the instrument may be of 

 use to chemists in the investigation of the molecular weights of 

 such compounds. 



The instrument is not quite so applicable for the specific heat of 

 solids as of liquids ; but it may be used for the former when they 

 are in powder or in small fragments. In this case the calorimeter 

 may first be heated by a known quantity of warm water, and the 

 solid at the temperature of the air be dropped in ; but this method 

 does not yield good results, there being no turning point in the 

 temperature. It is better to heat the solid in a small steam or 

 water bath, and drop it into a known quantity of water contained 

 in the cup of the calorimeter, the heat capacity of which is in- 

 creased by this amount, so that its constant now becomes K±. The 

 solid may, of course, be weighed beforehand, so that the simpler 

 unbalanced calorimeter can be employed. 



