214 Dr Turner's Chemical Examination of Wad. 



As the method of analysis is precisely similar to that so fully 

 described in my former communication, it would be superflu- 

 ous to enter minutely into particulars. The mineral dissolves 

 readily in muriatic acid with evolution of chlorine, leaving 

 only traces of insoluble earthy matter. The solution was com- 

 pletely free from iron, and, in addition to manganese, con- 

 tained only a small quantity of baryta. Exposed to a red 

 heat, after being well dried at a temperature of 212° F., it 

 yielded 10.66 per cent, of water, together with some oxygen. 

 At a white heat it lost 19.48 per cent. ; namely, 10.66 of 

 water, and 8.82 per cent, of oxygen. The baryta, precipita- 

 ted in the usual manner by sulphuric acid, amounted to J .4 

 per cent. — According to this analysis, 100 parts of the mineral 

 were resolved into 



100.00 



The essential ingredient of the mineral, inferred from these 

 numbers, appears to be a hydrated peroxide of manganese, 

 consisting of 88 parts or two equivalents of peroxide, and 9 

 parts or one equivalent of water, — a compound which, to my 

 knowledge, has not been observed in the mineral kingdom. 

 Were such a compound quite pure, the analysis should have 

 given the following proportions : — Red oxide 79.12, oxygen 

 10.57) and water 9 ; — that is, rather less water and rather 

 more oxygen than was actually obtained. A slight excess of 

 water must of course be looked for ; because the heat of 21 2° 

 cannot be expected to disengage all the humidity adhering to a 

 light earthy powder. A deficiency in oxygen is also to be ex- 

 pected. For the baryta which the mineral contains, and 

 which I shall show to be an accidental admixture, is not in its 

 ordinary state of combination, but is united with some oxide 

 of manganese. What that oxide is, has not yet been deter- 

 mined with certainty ; but in three minerals in which I have 

 detected a composition of this nature, — namely, in a Wad to 



