W. F. Hillebrand — Vanaditom Sulphide, Patronite. 149 



The determinations with the two highest ratios were earlier 

 analyses in which least free sulphur was found and presumably 

 least oxidation had taken place. They point to a formula 

 VS 4 for the sulphide instead of VS 3 as reported by Bravo, 

 whose actual ratio was 3'28. A sulphide of this composition 

 seems very singular and the possibility suggested itself that the 

 compound might be ortho-sulphovanadic acid, but this would 

 probably be soluble in water and an amount equal to that in 

 the ore would need, moreover, above 1 per cent of hydrogen, 

 whereas the total as represented by the water found is less 

 than 0-20 per cent, and this unquestionably belongs largely 

 with the siliceous and aluminous matter of the ore. 



In the light of the observation relating to the splitting off of 

 free sulphur from the sulphide, a process that is evidently 

 connected with exposure to air, the possibility has to be 

 considered that the free sulphur found in the test showing 

 least may all have been originally combined with the vanadium 

 to form a still higher sulphide than VS 4 . The ratio calculated 

 on this basis is less than 1 to 4'5, indicating a formula not 

 above V 2 S 9 . Lacking, as we do, any knowledge regarding the 

 higher sulphides of vanadium, speculation at present would be 

 premature. 



Whatever may be the true formula, the mineral is new and 

 the name patronite may well be applied to it. 



The Ir 07i- Nickel Sulphide, a Highly Nickeliferous Pyrite. 



The bulk analysis of the ore indicates a greater percentage 

 of the iron-nickel sulphide than would be supposed by inspec- 

 tion, and than was obtained by separation in the manner 

 already outlined. Much of it is evidently in a state of fine 

 division and escapes in the washings. Indeed, it was sought 

 to recover only the grains of some size. It was noticed 

 after separation that while some of the larger grains especially 

 showed the pyritous color on fracture surfaces, all were more 

 or less covered with a black coating of what is assumed to be 

 the carbonaceous material of the ore and that most of them 

 were black throughout, apparently from the same cause since 

 on solution in nitric acid a considerable carbonaceous residue 

 was left. In a few instances apparent crystals, seemingly of 

 octahedral habit, were observed, but otherwise the fragments 

 were quite destitute of crystalline structure. The color is 

 rather whiter than that of pyrite, as said before, becoming 

 of a reddish cast by tarnish. The mineral is not attracted by 

 a hand magnet but attaches itself readily to an electromagnet. 

 The density of the material analyzed was 4*33, but this value 

 is of little worth since, despite repeated purification, the frag- 



