20 



Transaction f^. 



The following was the result :- 



* Temperature, 0-05°. 



It is evident that somewhere between 25 and 20 atmospheres pressure 

 of CO2 a sudden change occurred in the nature of the solution, the con- 

 ductivity undergoing a remarkable drop. As other experimenters had ob- 

 tained evidences of a hydrate of CO2 existing at low temperatures and high 

 pressures, it was assumed that the change in conductivity was due to the 

 formation of the hydrate. 



The values of conductivity obtained at 25, 8, and 5 atmospheres pressure 

 show that, apart from the influence of the hydrate, the conductivity of the 

 solution under descending pressures follows closely that mider ascending 

 pressures, being in each case somewhat higher. 



The remainder of the experiments consisted in an attempt to determine, 

 by varying both pressure and temperature, such properties of the hydrates 

 as capacity for super-cooling, temperature of transition under various pres- 

 sures, degree of variation with temperature of conductivity of hydrate 

 or of solution, &c. Though consecutive with Series II, they will for con- 

 venience be designated Series III, and in most cases details will be omitted. 



Series III. 



A. An attempt to determine the pressure under which formation of the 

 hydrate would take place. Temperature, 0°. 



Pressure very gradually raised to 30 atmospheres, with the following 

 results : — 



