W. F. Hillebrand — Vanadium Sulphide, Patronite. 145 



1906, and that of Bravo bears the date Aug. 31 of the same 

 year, hence must have appeared a little later, although in the 

 August number of the Boletin de la Sociedad de Ingenieros. 

 Hewett's name, therefore, has the right of priority and being- 

 shorter is preferable, even though that given by Bravo may 

 better conform to Spanish usage as to derivation, since it 

 embodies the whole patronymic. 



The following analyses given by those authors show the 

 composition of the ore incompletely, since appreciable percent- 

 ages of nickel and titanium were overlooked, and, moreover, 

 they also show that it varies much in respect to the relative 

 amounts of siliceous and sulphide components. 



Analysis by Analysis by 



J. O. Handy H. Bunting 



(Pittsburg) (Lima) 



Si0 2 10-88 22-22 



Al o 3 3-85 8-32 



Fe.. 2-45 1-98 



V... 16-08 15-36 



Mo0 3 -. 0-50 



S soluble in CS„ 6-55 



S combined 54*06 r 



CaO , 0-33 



Moist u re trace 



Undetermined [5-63]* 9-98f 



[100-00] 100-00 



Both I (in Mr. Hewett's paper) and Bravo reported the 

 solubility of the vanadium in fixed caustic alkalies, and Bravo 

 likewise in ammonia. I may say that ammonia does not act so 

 quickly as the fixed alkalies. Bravo analyzed the alkaline 

 extract for sulphur and vanadium, after first removing free 

 sulphur, and reported 32*89 per cent vanadium and 67*20 per 

 cent sulphur, corresponding approximately to the formula VS 3 

 the ratio as calculated by me from his values is 1: 3*28). 



The complete analysis of this ore is extremely difficult and 

 in some respects the results given on p. 147 is lacking in precision. 

 The following behavior threw light on the nature of the min- 

 eral components. 



Repeated treatment in a Soxhlet extractor with carbon 

 disulphide removed considerable sulphur. After thorough 

 drying of the capsule and contents, hot water was passed 

 through. The aqueous filtrate was blue-green and held a sul- 

 phate or sulphates of vanadium. This operation was followed 

 by extraction with warm caustic soda as long as the filtrate 

 came through colored. Hereby nothing but vanadium, sulphur 

 and some of the siliceous components were taken out, and the 

 * Largely carbonaceous. f Carbon. 



