24 On the Elastic Forces of Vapours in vacuo and in Gases. 



Second series, January 18. 

 In this second series the balloon was surrounded by a freezing 

 mixture to cause the congelation of the acid. 



If the curve of the elastic forces be constructed from these 

 elements, it appears that the solid and liquid acid give two sepa- 

 rate curves which probably unite at the point of fusion ; the 

 curve of the solid acid is constantly above that of the liquid acid, 

 the tensions of which are always weaker at equal temperatures. 



Third Series. 



As it was feared that the acid employed in the two former 

 series might have contained a little water, it was distilled over 

 anhydrous phosphoric acid. But it was found that a certain 

 quantity of acetone was then always formed. To separate this 

 the substance was again distilled, only the last quarter of the 

 product being collected ; upon this the experiments were made. 



