Hai'old N. Allen, 



LATENT HEAT OF VAPORIZATION OF CARBON 

 BISULPHIDE. 



A large number of experiments were made with this com- 

 pound, several different bodies being tried to condense the 

 vapor. The best results were obtained with a plate of nickel, 

 weighing 24.10 grams, which was rolled into a spiral and 

 suspended over the lid of a platinum crucible, a shallow cup 

 of platinum foil being hung beneath this. The whole weight 

 of platinum was 6.98. This combination under the circum- 

 stances of the experiments condensed more than 0.8 grams 

 of carbon bisulphide. 



In an experiment made July 29, 1889, the initial temper- 

 ature of the calorimeter was 18.9, while the temperature after 

 the admission of vapor was 46.4. The thermometer used 

 was compared with a standard thermometer which had been 

 corrected at the Reichs-institut. 



The apparent increase of weight was 0.929 grams, and 

 to this must be added a correction of 0.0083 grams due to 

 reduction of the weights to vacuo. 



The equation 



( PFi5i + WS^ {T-t)=w\ 

 becomes 



(24.10 + 0. 10916 + 6.98 X 0.0323) 27.5 =o.9373\, 



the number 0.109 16 (Regnault) being taken as the specific 

 heat of nickel, and 0.0323 (Violle) as that of platinum. Thus 

 this experiment gives 



X = 83.79. 



The following is a list of all the successful experiments 

 made with the spirally rolled nickel, two being left out which 

 failed on account of the gradual increase of impurity in the 

 carbon bisulphide, and one in which the draught was not at 

 work. The carbon bisulphide used in the last three experi- 

 ments was carefully freed from water by distillation over 

 phosphorous pentoxide. Admixture of water or of some 



