MABERY AND GOLDSTEIN. — SPECIFIC HEATS OP HYDROCARBONS. 541 



Each hydrocarbon had been separated by a long process of distillation, 

 and purified, by treatment with sulphuric acid, sodic hydrate, and drying 

 over sodium. 



The determinations were made in a Bunsen ice calorimeter, to which 

 was attached a capillary side tube 70 centimeters long, and the bore of 

 such size that 1 centimeter contained 0.0579 grams of mercury. To 

 maintain the temperature at 0°, the calorimeter was placed in a jar ot 

 ice-water with an excess of ice, and this jar was placed in another jar 

 and the space between filled with cotton. The calorimeter was filled 

 with air-free water and dry mercury, and the inside film of ice, 2 to 3 

 millimeters thick, was formed by evaporation of ether by an air blast 

 within the inner tube. Approximately 2 grams of the hydrocarbon was 

 placed in a small glass stoppered tube of thin glass, whose heat equiva- 

 lent was determined. The tube and hydrocarbon were heated to 50°, 

 in a larger tube placed in a beaker of water, kept at this temperature 

 for at least 15 minutes, then transferred by a thread to the calorimeter, 

 ^ith care this could be done without loss of heat by radiation. The 

 contraction of the mercury column was from 15 to 25 centimeters. 



This method can be used for the paraffine hydrocarbons from C 6 H 14 to 

 C 16 H 34 , the limit at which the hydrocarbons remain wholly liquid at 0°. 



After obtaining the water constant of the apparatus, three to six de- 

 terminations of each hydrocarbon were made at the temperatures 0° and 

 50°, with results given in the following table : 



