282: M. R. Phillips on the Oxides of Manganese. 



ness of your analysis : allow me however to observe, that if in 

 my experiments upon the Warwick ore, I had committed any 

 error in ascertaining the quantity of water, as you seem to think 

 probable from the nature of my apparatus, this near agreement 

 with you as to the proportion yielded by the Ihlefeld manga- 

 nite, will, I trust, remove all ground for suspicion on this 

 head. 



Those portions of the Warwick ore which you had selected 

 and sent me as manganite nearly pure, were next subjected 

 to examination; an accident however happened, which pre- 

 vented me from arriving at any positive conclusion, and I had 

 not sufficient to repeat the experiment; but still I have not the 

 slightest doubt, that these fragments were manganite as you 

 stated them to be, for on comparing a small remaining por- 

 tion with some of the Warwick oxide, I find that a great pro- 

 portion of the latter is manganite, and in many cases perfectly 

 unmixed with any other oxide. 



I have also again minutely examined the specimen of War- 

 wick oxide, which I have stated to be a compound of 4 atoms 

 of manganese, 7 atoms of oxygen, and 1 atom of water. And 

 although I have varied my experiments, I have in every in- 

 stance obtained fresh results, confirming my former determi- 

 nation- 

 Some time since I sent you a considerable quantity of this 

 ore, and which I have no doubt you have mistaken for pei'- 

 oxide, since they greatly resemble each other in appearance and 

 softness : you will now much oblige me by furnishing me with 

 the results of your examination of this oxide, and I shall feel 

 exceedingly gratified in having my experiments confirmed by 

 so skilful an analyst as yourself. From the slight examination 

 which I had made of the Warwick ore, when I gave you a 

 specimen of it, I did not suspect that portions so similar in ap- 

 pearance, though, as you have since pointed out, so dissimilar 

 in hardness, were really different oxides ; there is now how- 

 ever no question, that what you examined was principally 

 manganite, while the mineral which I analysed was the new 

 oxide, and which, should you agree with me as to its compo- 

 sition, I propose to call Varvicite. 



I am happy to find that you agree with me in some of my re- 

 marks on the red sulphate of manganese, and I feel confident 

 that in pursuing your researches on this subject, you will find 

 that its colour is owing to the presence of the deutoxide and 

 not of the red oxide of manganese, as you suppose in your 

 original memoir. I have now kept different portions of this 

 solution exposed to air and light, and also excluded from both 

 for about ten months; the colour has not in any instance suf- 

 fered 



