512 



A. C. LANE MINE WATERS AND THEIR FIELD ASSAY 



Magnesmm. — Mr Charles Catlett^* has described a field test for mag- 

 nesia dependent on the fact that lime is much more soluble in sugar than 

 magnesia, which ought to be made availaljle. Good field tests for mag- 

 nesium and sodium are still lacking. 



Sulphates. — The turbidity tests for sulphates is on the precipitate made 

 in an acid barium chloride solution, and the method devised by Jackson 

 and used by Leighton has been recently reexamined by Parr.^^ 



Sulphur. — The browning by acetate of lead has been used, but is hardly 

 quantitative. 



COLORIMETRIC TESTS 



Instead of standard comparative solutions, tinted glasses may be used. 



Leighton's test for iron with KCNS involves carrying nitric acid 

 around, which is awkward. 



The ink test with tannin — that is, cold tea — is quite as delicate, but the 

 resultant tint varies, being violet in carbonated waters, cider-colored if 

 ammonia is added, and discharged by acids. It may be used comparatively 

 in one suite of waters. Perhaps it would be better to always make the 

 solution alkaline. 



" Bi-monthly bulletin of the American Institute of Mining Engineers, September, 1907. 

 -"■ Bulletin no. 3, Illinois Geological Survey. 



