865 



§ 20. In tlie case of Potassiumchlorate : KCIC\ , the maximum 

 pressure B was 3,573 mm. mercury at 413°. 5 C; at 443°. 5 C. 

 it was: 3,540 mm. The radius of the here used silver-capillarj^ tube 

 being: =0.03460 cm., the free surface-energy is calculated: 



At 413°.5 C. x = 82,4 Erg. pro cm^ 

 At 443°.5 C. x = 8J,6Erg. pro cm^ 



At the last mentioned temperature the salt commenced to decompose 

 already distinctly, while 0, was split otF; at higher temperatures 

 therefore the values of x appeared to increase gradually by the 

 generation of KCIO^ and [vCl. 



It was not possible therefore to investigate the values of the 

 temperature-coefficients at higher temperatures; in every case however 

 they seem to be rather small. 



With SiLVERNiTRATE : AgjSFO^, the value of x is about 164 Erg. 

 pro cm=. at 280° C; at 410° C. it is about 153.8 Erg. In this case 

 the temperature-coefficient is also in the neighbourhood of 0.6 or 0.9, 



— this being a rather small value too. 



§ 21. It is not my intention, to discuss now already the here 

 mentioned data, nor to add the remarks, which are suggested thereby. 

 It is better to postpone that task, until the complete experimental 

 material now a\'ailable will be published. The given instances may 

 however prove, that the question : hoic to measure the surface-tensions 

 of liquids loith great accuracy within a temperature-interval, from 



— 80° C. to 1650° C, may be considered now as completely solved. 



Groningen, May 1914. Laboratory of Inorganic Chemistry 



of the University. 



Chemistry. — ''The Temperature-coefficients of the free Surface- 

 energy of Liquids, at Temperatures from — 80° to 1650° C". 

 II. Measurements of Some Aliphatic Derivatives. By Prof. 

 Dr. F. M. Jaeger and M. J. Smit. (Communicated by Prof. 

 P. V. Romburgh). 



§ 1. In what follows the data are reviewed, which were obtained 

 by us in the study of a series of aliphatic derivatives after the' 

 method formerly described by one of us^). 



With respect to the liquids here used, we can make the following 

 general remarks. No product of commerce, not even the purest ob- 



1) F. M. Jaeger, These Proeeedings (1914). 



