ON PURE SULPHATE OF MANGANIUM. 
57 
ART. XIII. — A SIMPLE METHOD FOR PREPARING THE PURE 
SULPHATE OF MANGANIUM FROM THE NATIVE PER- 
OXIDE. 
By Mr. Reuben Phillips. 
The native peroxide of manganinm is to be pulverised 
and suspended in water, through which a stream of sulphu- 
rous acid gas is to be passed. The same arrangement of 
apparatus may be used, as would be employed were it de- 
signed to generate the hyposulphate of manganium ; with 
this exception, that, there is no occasion for keeping the 
water containing the peroxide of manganium cool. The 
sulphurous acid, generated from sulphuric acid, should be 
made to traverse some vessel containing water, to condense 
any sulphuric acid which may be suspended in the gas, and 
also to remove from the gas any hydrochloric acid gas, 
which may be simultaneously liberated with the sulphurous 
acid ; when the commercial sulphuric acid is used, I send 
the sulphurous acid through a U tube containing fragments 
of pumice-stone, which are saturated with water ; and I 
also put some water in the tube, so that the gas may bub- 
ble through a verticle inch or two of water. The sulphu- 
rous acid is then conveyed into a two-necked bottle, con- 
taining the oxide of manganium suspended in water ; and 
through the other neck of the bottle, a stirrer is inserted to 
prevent the oxide from subsiding. 
The sulphurous acid becomes rapidly absorbed in the 
two-necked bottle, producing the sulphate and hyposulphate 
of manganium ; to transform which latter salt into the sul- 
phate of manganium, the contents of the two-necked bottle 
is to be transferred to a porcelain vessel, in which it can be 
boiled for about half an hour ; at the end of which time, the 
hyposulphate will be very nearly decomposed ; an excess of 
