356 IRON, NICKEL, COBALT, &c. 



dized by steam, combine with 29*87 grains of 

 oxygen.* This is nearly the same result as I 

 obtained. But from the subsequent experi- 

 ments of Gay-Lussac it would appear that iron, 

 oxydized in this* manner, unites with more oxy- 

 gen than was found either by Bucholz or my- 

 self. He found the oxide composedt of 



Iron 100 or 3-5 



Oxygen 37'8 - 1-323 



Now, 1*323 is very nearly 1^ oxygen. Hence, 

 it would appear that this supposed oxide is a 

 compound of 1 atom iron + 1^ atom oxygen. 

 Now, this is just the proportion of oxygen which 

 would result from the combination of 1 inte- 

 grant particle of protoxide, and 2 integrant 

 particles of peroxide of iron ; for 



1 atom protoxide is composed of 3-5 iron -f- 1 oxygen 



2 atoms peroxide of . 7 +3 



Total . . . 10-5 4 



And l 3 - = 3-5 ; and j = 1 j. So that such a 

 compound would obviously consist of 1 atom of 

 iron, and 1 atom oxygen. 



When this oxide of Gay-Lussac is dissolved 

 in sulphuric acid, and alcohol poured upon the 

 sulphate, a solution of persulphate of iron is ob- 



* Nicholson's Jour. XXV. 353. f Ann. de Claim. LXXX. 164. 



