( 464 ) 



of investigations, whicli Smith and Holmes ^) made with a view to 

 determining the points of solidification of mixtures wliich contain 

 much Sv, which series is called by them "Zweite Reihe", it says : 

 "Die zweite Reihe nmfasste nur vier Messungen. Nach deren Aus- 

 fiihrung wurden mehrmals versncht, Beobaohtungen zu erzielen an 

 Proben, in welchen noch grössere Mengen amorphen Sclnvefels dem 

 Riickgang wahrend des Abkühlens entgangen waren, mul welche 

 entsprechend niedrigere Gefrierpunkte zeigten. Von diesen war nur 

 ein Versuch, No. 5, erfolgi-eich. Um iibernuissiges Abkidilen und 

 stellenweises (jefrieren zu verhiiten, musste luimlich mit dem Abkiiiden 

 sorgfaltig vorgeschritten werden, und es verschwand notwendig immer 

 der Hauptteil des gebildeten amorphen Körpers". 



In the cited fifth ex|)eriment they observed a point of solidification 

 of 112°.45, and the S„-content amounted to 5.29 "/„ by weight. 



In oui- investigation sulplnir was heated in a glass tube of a dia- 

 metei- of =t VI., cm. uj» to 400°. At this temperature first NH^ was 

 led through the tube to accelei-ate the establishing of the equi- 

 librium, and then ^VAj, to facilitate the freezing of the ecpiilibriuni 

 with rapid cooling. Then the sulphur was cooled as rapidly as 

 possible in a strong cold current of air down to some degrees above 

 the unary point of solidification of the monoclinic modification. Then 

 the tube was placed in another, which was J cm. wider, which was 

 in an oil-bath of a temperature ^b 5° lower than the exi)ected point 

 of solidification. In the first experiment no .SY), was passed through, 

 and the cooling took place slowly by simply leaving the tube e\j)Osed 

 to the air for some minutes till the temperature had fallen to ± 117°. 

 After it had been placed in the bath of 110°, the sulphur was seeded 

 with monoclinic sulphur after a slight undercooling of ± 0,5°, after 

 which the temperature rose to 114°, and remained there till the whole 

 mass was solid. 



So the unary tem{)eratnres of solidification had been i-eached except 

 for a halt degrees. After having repeated this experiment a few 

 times, we proceeded to the method of working described above, 

 and we tried to get a point of solidifii'ation as low as possible by 

 "freezing" the equilibrium at higher temperature. 



Quite in accordance with earlier investigators we found that in 

 this way lower points of solidification could indeed be observed, but 

 that they always remain above 110°, but what others possibly did 

 not see so clearly in consequence of their too rough method of inves- 

 tigation was this that the point of solidification is always low^est at 



1) Zeitschr. f. pbys. Ghem. 42, 476 (1903). 



