148 W. F. Hittebrand — Vanadium Sulphide, Patronite. 



Free Sulphur and Water- Soluble Extract. 



Several determinations of the sulphur extractable by carbon 

 disulphide were made at considerable intervals of time. The 

 first gave 4*5 per cent, the second 5 - 5, and the third 7 per cent, 

 thus, as already said, indicating a progressive liberation of free 

 sulphur. The extractions were made in a Soxhlet apparatus 

 til Ian extract was found free from sulphur. 



The first determination of the water-soluble extract gave 

 0*41 per cent S0 4 and the solution held vanadium, as shown by 

 its blue-green color and by qualitative test. Much later, in 

 another portion, there was found 1/23 per cent S0 4 and 0'92 

 per cent Y, with ratio Y to S0 4 of 1 to 071. The vanadium 

 was in an intermediate stage of oxidation between Y 2 4 and 

 Y 2 B , as ascertained by direct titration and again after reduc- 

 tion by sulphurous acid. 



When the powder that had served for the last test, and 

 which had afforded 7 per cent free sulphur, was allowed to dry 

 and left exposed to the air for three weeks and then again 

 extracted by carbon disulphide and hot water in turn, there 

 was found additional OS L per cent of S0 4 and 0*40 per cent of 

 Y, but the vanadium of the aqueous extract was all in the Y 2 4 

 state, for after titrating directly and then again after reduction 

 by sulphurous acid, the results were identical. The ratio of Y 

 to S0 4 was not, however, the same as in the previous test, being 

 1 to 1*07. In this last test there was found 3*83 per cent of free 

 sulphur in addition to the 7 per cent found at first, and since the 

 sulphur in the S0 4 is but - 27 per cent, or but one-fourteenth 

 of the free sulphur formed during the three weeks, the ground 

 will be apparent for the earlier remark (p. 146) concerning the 

 greater rapidity of splitting off of free sulphur from the origi- 

 nal sulphide than of oxidation of the lower combination of 

 vanadium and sulphur that presumably resulted from this 

 division. But the variation in the two ratios given above 

 between vanadium and S0 4 has not been cleared up. These 

 approximate very roughly to 1 to 1, which indicates a similar 

 ratio in the lower sulphide, to whose direct oxidation the sul- 

 phate is supposed to be due, that is, YS. But much more 

 knowledge is needed, based on numerous and varied tests, 

 before the reactions involved in the changes above indicated 

 can be written. 



Patronite. 



Several determinations of the sulphur and vanadium in the 

 alkaline extract, after first removing free sulphur and the 

 water-soluble constituents, gave the following results : 



Y 19-16 18-89 19-09 *18'46 



S 47-74 47-84 45-65 44'74 



Ratio Y:S 1:3-97 1:4-04 1:3-82 1:3-87 



