269 



cogency as a proof of the existence of an active and an inactive 

 kind of molecules in ammonia. 



I wanted to test my supposition in another way and took, accord- 

 ingly, an entirely different course. 



After having convinced myself that the pure P,0, which I prepared 

 by Baker's method, had really the same |)roperties as that of Bakkr'), 

 I began with some of my pupils an investigation of the influence of 

 intensive drying on the point of transition, the melting-point, the 

 vapour tension of the solid and liquid state, and the electrical resistance 

 of the liquid phase of a great number of substances, and among them 

 those substances, of which Bakek found that the chemical activity 

 disappeared by intensive drying, occupy a very particular place on 

 account of the great importance of this phenomenon. Of this latter 

 group first of all NH,, HCI, CO, and (), were taken in hand. 



In a following communication our results aiul the particulars of 

 the experiments will be discussed. 



Laboratory of General and Inorg. 

 Chemistry of the University. 



Amsterdam, March 20'i' 1923. 



') I became acquainted with this method through a private communication by 

 Prof Bakke before it was publislied. which saved me a great deal of trouble 

 and lime. I will avail myself of this apportunity to express my cordial tlianks to 

 Prof. Baker for his kindness. 



18* 



