240 Kraus and Hunt — Sulphur and Celestite. 



holds good of many of the celestite-bearing rocks of central 

 New York — are treated with dilute acid, hydrogen sulphide is 

 liberated together with the carbon dioxide. Even boiling in 

 water is sufficient to give rise to the liberation of the sulphur- 

 eted hydrogen. To be sure, in some instances, the amount is 

 very small, but, nevertheless, even a trace is of great import, 

 indicating that a sulphide decomposed by hot water is present. 

 Such a sulphide is doubtlessly strontium sulphide. Hence, we 

 must consider the theory that the decomposition of pyrite or 

 marcasite by the formation and subsequent oxidation of hydro- 

 gen sulphide has given rise to the native sulphur at this quarry 

 as untenable. 



However, when we consider that the uppermost strata con- 

 tain about 14 per cent of strontium sulphate, which is quite 

 soluble in water and, hence, easily transported to the lower 

 layers, and, secondly, that these and the lower strata contain 

 considerable quantities of organic matter ; thirdly, that there 

 is only a negligible amount of iron present, and lastly, that 

 hydrogen sulphide is easily liberated by hot water, it seems 

 evident that the celestite, present in a disseminated condition 

 and which has by the action of the organic matter become par- 

 tially reduced to the sulphide, must be considered as the 

 source of the hydrogen sulphide. 



Therefore, if the foregoing statements be true, an analysis 

 of one of the more porous and cavernous layers, the cavities of 

 which contain native sulphur, ought to show not only the 

 presence of strontium as a sulphate but also as a sulphide, 

 which would be indicated in the analysis as sulphur trioxide 

 and sulphur, respectively. Such an analysis was made with 

 the following results : 



Per cent. Ratio. 



SiO„ 20-14 



Fe A j , . 86 



Al„0 3 j ° bb 



CaO 19-56 0-3493 



MgO 15-32 0-3795 



SrO 0-66 0-006371 



BaO 0-07 0-000457 



S ._■ 0-02 0-000587 



S0 3 0-56 0-006994 



CO„ 31-94 0-7259 



Na 2 "0 ._ 0-09 



K„0 ... 0-07 



CI 0-03 



Orsranic matter* 10-72 



100-00 

 * By difference after deducting the oxygen equivalent of the sulphur. 



