330 PERSALTS 



tals, while weighing, accounts for the small sur- 

 plus of soda in the liquid after mixture : this is 

 also the reason of the slight deficiency of oxide 

 of iron found in the first part of the analysis. 

 The salt is obviously composed of 



l atom nitric acid 1O125 



1 atom peroxide of iron 5 

 8 atoms water . 9 



24-125 



4. Subpernitrate of iron. This salt, obtained 

 by drying the pernitrate in rather a high tem- 

 perature, has been analyzed by M. Grouselle, 

 who found its constituents as follows : 



1 atom nitric acid 6-75 

 8 atoms peroxide of iron 4-0 



2 atoms water . 2-25 



49* 



Persesqui- 5. Pei'sesquiphosphate of iron. This salt is 

 phosphate, eas 'jy f orr ned by mixing solutions of persulphate 

 of iron and phosphate of soda together in the re- 

 quisite proportions. It is a white powder, taste- 

 less and insoluble in water. 



To determine the composition of this salt I 

 proceeded in the following way : 173*75 grains 

 (equivalent to 10 atoms) of the crystals of pro- 



* Ann. de Chim. et dc Phys. XIX. 138. 



