( 559 ) 



times (T) are mentioned at wliicli the tmnsformation has proceeded 

 halfway. 



A. Influence of the Concentration of Sidi)hnnc Acid, 

 t = 25°. 0,5 cc. siilphiii-ic acid, 

 acid a I b I c Id 



5 mill. 49 sec. | 2 liours 57 m. | 13 li. 40.5 m. | very slowly 



t =1 25°. 1 CC. sulphuric acid. 



T. 



acid a 

 too rapid 



7 h. 45 111. 



25 111. 44 s. I 2 h. 38.5 m. 

 B. Influence of the Quantity of Sulphuric Acid 

 t = 25°. acid a. 



i cc. 



0.6 cc. 



too rapid | too rapid 



0.5 cc. 

 5 m. 49 s. 



0.3 cc. 

 3 li. 8 m. 



t = 25\ acid I). 



2 cc. 



1.5 cc. 1) I 1.25 cc. 



T. ! too rapid | too rapid | 25 m. 44 s. 



4 cc. 



0.5 cc. 



55 m. 20 s. 2 li. 57 m. 



0.25 cc. -) 



1.5 cc. 

 T. i li. 16 ui. 



t = 25°. acid c. 

 1 cc. 



1. 2 li. 32.4 111. 



2. 2 h. 38.4 111. 



0.5 cc. 

 13 h. 40.5 m. 



C. Influence of the Temperature. 

 Acid a. 



T. at t = 35° 

 » 25° 



0.5 cc. 



0.3 cc. 

 6 ni. 12.5 s. 1 



5 111. 49 f.j _^ J (J 3 h. 8 111. ) 

 58 m. 45 s. \ ^"^"^« I 



± 30 

 times 



0.2 cc. 

 32 m. 33 s. 



T. at t = 35'^ 



Acid b. 

 1 cc. 



25° 25 m. 44 s. j ^ 

 -150 (1 h. 15 m.i *^'"''^ 



^ Transformation almo.sl completed after :20 niimilcri. 



^') Not yet decomposed to the extent of l.j "/,) after 21 hours. 



Proceedings Royal Acad. Amsterdam. Vol. V. 



38 



