146 IF. F. Hillebrand — Vanadium Sulphide, Patronite. 



solution was of a cherry-red color. In it the proportions of 

 vanadium and sulphur were determined. 



It may be said here that the analysis was of necessit} T made 

 with interruptions, and it was noticed that the values obtained 

 for free sulphur increased with lapse of time. The first deter- 

 mination gave 4 5 per cent, the second 5 - 5 per cent, and the 

 third 7 per cent sulphur, each on a separate portion of the same 

 sample. This seemed to indicate a progressive oxidation of the 

 vanadium sulphide with liberation of free sulphur, or else that 

 the ore contained insoluble as well as soluble sulphur and that 

 the former on exposure of the powder to air underwent rather 

 rapid conversion to the soluble modification. Heating the 

 powder for some hours with a little carbon disulphide in a 

 sealed tube in a steam bath did not result in an increased yield 

 of free sulphur, nor did heating the powder to 60° for some 

 hours in the air do so, hence the latter explanation seems 

 improbable. To test the former the portion of powder that 

 had afforded 7 per cent sulphur and had then been extracted 

 by hot water was allowed to dry thoroughly and left exposed 

 to air under an inverted beaker for three weeks, after which 

 time it was again tested for free sulphur and sulphate, both of 

 which were found, thus apparently confirming the supposition 

 of oxidation. But the free sulphur found in this test was so 

 far in excess of that converted to sulphate that it would seem 

 as if the liberation of sulphur took place much faster than the 

 oxidation of that which remained in combination with the 

 vanadium (see page 148). 



It was impracticable satisfactorily to examine the material 

 remaining in the Soxhlet capsule after extraction by carbon 

 disulphide and water, but separate portions of the ore, treated 

 directly with alkali, were used in part. From the residue thus 

 obtained strong nitric acid after a few minutes action took out 

 all the iron-nickel sulphide together with most of the remain- 

 ing vanadium, all the molybdenum and some titanic oxide, 

 silica and alumina, besides acting to a slight degree perhaps on 

 the carbonaceous component of the ore. The sulphur of the 

 metallic sulphide was apparently wholly oxidized by the nitric 

 acid. The solution was analyzed, but for more exact deter- 

 mination of the composition of the sulphide large amounts of 

 the ore, only coarsely broken up, were thoroughly extracted 

 by alkali, the black residue was dried and rubbed down gently 

 with the linger, and from it the sulphide was extracted by an 

 electromagnet and purified by repetition of the treatment. 



The residue not dissolved by nitric acid is black and con- 

 tains most of the carbonaceous matter of the ore besides the 

 titaniferous and siliceous matters not removed by the forego- 

 ing operations. The carbonaceous material contains much 

 sulphur and seems in this respect to resemble the quisqueite 



