255 



of hydrogen, which at tlie same time simplified oiu- calculations 

 considerably. 



Henceforth tlie sohitions were prepared with boiled water. 



They were analj'zed as well by precipitating with ammonia as by 

 reducing with potassinmpernianganate ') ; in the first case we oxy dated 

 with nitric acid till the entire tiansformation into ferric-salt had 

 taken place-, whereas in the second case the permanganate was 

 tested with oxalate; the second method proved sodium the most 

 reliable (accuracy 4 7oo)- 



Save the ferrous sulfate of Mkrck, all the material was provided 

 by Kahi.baum. 



The ferrous ammoniumsulfate was the so-called "Manganfreie 

 Morsche Salz". On account of the ferric-salts, examined till then '), 

 we could expect a dependence of the number of magnetons on the 

 concentration with ferrous-salts as well. 



However, our experiments showed an absolute constancy of this 

 number as may be seen from the following tables: 



TABLE I. Ferrous sulfate. 



1) Treadwell, Quantitative Analyse. 



^) B. Cabrera et E. Moles, Mai 1913 Arch, des Sc. Ph. et N. Geneve, whose 

 results were on Ihe whole confii'ined by our own experiments (not published though). 



