150 IF. F. Hillebrand — Vanadium Sidphide, Patronite. 



ments contained a good deal of carbonaceous, siliceous and 

 titaniferous matter in a state quite invisible to the eye. Heated 

 in a closed tube much sulphur is evolved. The mineral is very 

 insoluble in hydrochloric acid but is readily attacked by nitric 

 acid with complete oxidation of the iron, nickel and sulphur. 

 The other constituents remain more or less unattached accord- 

 ing to the duration of contact with the acid. 



The results given below are for the four chief constituents 

 the mean of concordant determinations. It is to be noted that 

 if the vanadium was counted as the element, every analysis 

 gave a summation of approximately only 97 per cent. This is 

 accounted for in part probably by the extreme oxidizability of 

 the mineral when exposed in powder form to the air, especially 

 when wet. Hot water - extracts from the powder ferrous and 

 nickelous sulphates with only a very little vanadium. If the 

 powder is left moist on the filter, relatively large additional 

 quantities of iron and nickel can be extracted next day, and 

 for several successive days, with very little vanadium. But the 

 discrepancy cannot be apparently in large part thus accounted 

 for. It seems necessary to assume that the vanadium is in an 

 oxidized form, perhaps as a constituent of the siliceous-alumin- 

 ous material. In this case its condition would be that of triva- 

 lency in all probability, a condition which also affords a more 

 satisfactory summation than that of quinquivalency. Against 

 its presence in combination with silica and alumina is its great 

 excess over that in which it is known to occur in such forms 

 in nature. On the other hand, the matter insoluble in nitric 

 acid still contains some vanadium. 



The following experiment seems to put it beyond question 

 that the vanadium is not a constituent of the metallic sulphide. 



Mean Atom. Ratio Calc. to 100 



S 45-06*-=-32-06 = l'455 = 2'02 52'31 



Fe 25-38 -=-55-9 = 0-454 ) . 29-46 



Ni ..... 15-70 -=-58-7 =0-267 f U / * j1 ~ 1 °° 18-23 



Co... trace 100-00 



V 4-31 =6-33 V a O, or 7-66 Y„0 B 



Mo ._ 0-09 



C-. 0-47 



H 2 1*38 (parti v from H of carbonaceous matter) 



TiO„ 0-93 



Si0 2 " 1-93 



A1 2 3 _. 2-45 (with a little P 2 5 ) 



97-70 



* This does not include the sulphur that may have been held by the undis- 

 solved carbonaceous matter. 



