Mr. Phillips oji a 7ie'w Oxide of Manganese ; ^-c. 215 



so little exceeding the weight of one atom of oxygen, that 

 upon the result of this and a similar experiment, I have 

 founded the admission which I have made. 



I now heated similar quantities of acid and peroxide; but I 

 stopped the operation when about 40 inches, or half the quan- 

 tity obtained in the last experiment, had come over. 



When water was added to the sulphate of manganese, I 

 found that a large quantity of brown oxide of manganese, spe- 

 cifically very light, was diffused through it ; it was evidently 

 oxide which had in this respect at least suffered consider- 

 able change ; it was separated by elutriation from 9 grains 

 of the peroxide employed, and which remained unaltered in 

 its properties; this altered oxide when washed and dried on 

 a sand-heat weighed 58*8 grains. 



To determine the nature of this altered oxide, 57 grains 

 were by a strong heat converted into red oxide, by which 

 they lost 6*8 grains, therefore 58*8 the whole quantity would 

 have given T'Ol grains : now as 132 of peroxide lose by this 

 treatment 16 of oxygen, 58*8 would be diminished 7*12; so 

 that the altered oxide is evidently peroxide. 



Knowing from previous experiment that red sulphate of 

 manganese is decomposed by a large quantity of water, I re- 

 peated the last detailed experiment, but with this variation : I 

 added to the sulphate of manganese only so much water as 

 was sufficient to dilute it enough to allow of its being filtered 

 through paper; by this I obtained, without regarding either 

 the altered oxide, or that which remained unacted upon, five 

 fluid ounces of solution of sulphate of manganese. The colour 

 of this was so intense a red, that when diluted with twice its 

 bulk of water, the mixture was as deep-coloured as port wine, 

 and in tint very closely resembled it. To half the solution I 

 added a wine pint of distilled water, precipitation immediately 

 took place, and when slighdy heated, the solution became 

 perfectly colourless, and 3 grains of peroxide were precipi- 

 tated; after the action of water potash threw down 27 orains 

 of oxide. It has been already mentioned, that the oxide pre- 

 cipitated by water is peroxide ; and I have found by repeated 

 experiments, that the protoxide precipitated by potash be- 

 comes deutoxide by drying. 



Assuming then, as in the former experiment, that 9 grains 

 peroxide and silica remained unacted upon, and that about one 

 grain of the 150 was soluble impurity, we may conclude that 

 14-0 of peroxide of manganese by losing 12*7 oxygen, were 

 converted into deutoxide, which formed deuto-sulphate with 

 the acid ; so easily, however, is this salt decomposed by water 

 into protoxide and peroxide, that even when employing the 



small 



