JOURNAL 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. io December 4, 1920 No. 20 



GEOCHEMISTRY. — Notes on the analysis of mineral sulphide 

 water. ^ J. G. Fairchild, U. S. Geological Stir\^ey. 



In the course of analysis of a sample of water from the Texas 

 oil field which was highly charged with alkaline sulphide, the 

 author was at a loss to find a method of detecting and estimating 

 not only the total sulphide sulphur but also the carbon dioxide 

 as half bound and wholly bound. When the soluble salt of a 

 heavy metal, such as cadmium chloride, is added to an alkaline 

 sulphide water an insoluble sulphide is formed and an amount 

 of hydrochloric acid is liberated equivalent to the sulphide pres- 

 ent; thus, 



MvSH + CdCl, = CdS + MCI + HCl 



where M is an alkali metal. 



If only the total sulphide and carbonate are to be determined, 

 the problem is very simple, for all that is necessary is to intro- 

 duce into a measured quantity of the mineral water undergoing 

 analysis the soluble salt of a heavy metal, acidify the water with 

 a small quantity of acetic acid, and absorb the liberated carbonic 

 acid in the usual way, but if the presence of bicarbonate is to be 

 determined, then a modification of this procedure becomes neces- 



' Published by i)ermission of the Director, U. S. Geological Survey. Received 

 Oct. 15, 1920. 



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