374" IRON, NICKEL, COBALT, &c. 



combination of peroxide of lead and deutoxide 

 of manganese ; and this precipitate he consider- 

 ed as containing all the oxygen and all the man- 

 ganese which existed in the manganous acid. 

 This precipitate, being washed and dried, was 

 mixed with bisulphate of potash, and exposed to 

 a heat capable of fusing it in a retort. The oxy- 

 gen gas given out was collected and measured ; 

 its weight was O1303 parts. The salt in the re- 

 tort was dissolved in water (the lead remaining 

 behind in the state of sulphate) ; the manganese 

 was precipitated by carbonate of soda, and ex- 

 posed to a red heat. The deutoxide obtained by 

 this process weighed O282 parts. 



Now, deutoxide of manganese is (as we have 

 seen) a compound of 3 '5 manganese +1-5 oxy- 

 gen ; consequently, 0-282 parts of this oxide 

 contain 



Manganese . 0-1974 

 Oxygen . 0-0846 



0-2820 



If to this portion of oxygen we add the O1303 

 parts driven off by heat, we shall have manga- 

 nous acid composed of 



Manganese 0-1974 or 3-5 

 Oxygen 0-2149 - 3-8103 



0-4123 



