376 IRON, NICKEL, COBALT, &c. 



there was combined just as much oxygen as with 

 the 0*350 parts in the manganous acid. 



But manganous acid is composed of 5 deu- 

 toxide of manganese + 1 *5 oxygen ; consequent- 

 ly, 0-350 are composed of 0*245 deutoxide + 

 0*105 oxygen ; and manganesic acid is a com- 

 pound of 



Deutoxide of manganese 0-214 

 Oxygen . . 0-105 



Deutoxide of manganese is a compound of 3*5 

 manganese + 1*5 oxygen; consequently, 0-214 

 deutoxide consists of 0*1498 manganese + 0-0642 

 oxygen. By adding together the 0*105 oxygen 

 and the 0*0642, we obtain 0*1692 for the whole 

 oxygen in manganesic acid, combined with 

 0*1498 of manganese. Thus it appears, that 

 manganesic acid is a compound of 



Manganese 0-1498 or 3-5 

 Oxygen 0-1692 - 4-620 



0-3190 



If we make the same allowance for excess of 

 oxygen that Dr. Forchhammer made in the case 

 of manganous acid, manganesic acid may be 

 considered as a compound of 1 atom manganese 

 and 4 atoms oxygen, which would make its 

 atomic weight 7 '5. 



It would appear from the preceding investiga- 

 tion, that oxygen and manganese combine in no 



