1865.] CHEMISTRY OP NATURAL WATERS. 277 



Thus of the waters of the latter class (§ 45), the alkalies of the 

 Nicolet spring calculated as chlorids contain 1.89 per cent of 

 chlorid of potassium, and those of the Jacques-Cartier 2.95 ; while 

 for the St. Ours spring the chlorid of potassium is equal to not 

 less than 25.0 per cent. There does not however appear to be any 

 relation between the proportion of alkaline, carbonate and that of 

 potassium, since the salts from the waters first named are more 

 alkaline than those of St. Ours ; while those of the alkaline water 

 of Joly contain less than one per cent of potassic chlorid. 



The amount of this salt obtained from the water of the Ottawa 

 River is worthy of notice, being equal to not less than 32.0 per 

 cent of the alkaline chlorids, while in the waters of the St. 

 Lawrence it amounts to 16.0 per cent.* A large proportion of 

 potassium relatively to the sodium has already been observed in the 

 case of many ordinary river and spring waters, and this is readily 

 explained when we consider the extent to which potash is set free 

 by the decomposition of both vegetal and mineral matters at the 

 earth's surface. The process by which this base is eliminated in 

 filtering through soils has already been explained in § 5. The 

 occasional presence of considerable amounts of potash in sulphated 

 mineral waters (Lersch, Hydro-chemie, p. 316) is explained by the 

 power of solutions of gypsum to set free this alkali from soils 

 (§ 7), and also probably in some cases by the dissolution of double 

 potassic salts like polyhallite. Strata holding glauconite, which 

 occurs alike in paleozoic and more recent formations,! may also be 

 conceived to yield potash salts to infiltrating waters. 



§ 53. It will be seen that the waters above noticed, in which the 

 proportion of the potash to the soda is large, are but feebly saline, 

 so that the real amount of potassium is in no case great. I have 

 however recently examined the water of a borax lake from 

 California, which contains in 1000 parts 17.250 of solid matters 

 of which 1.818 is carbonate of potash, the remainder being soda- 

 salts, carbonate, borate, chlorid, and a little silicate, with no sulphate 



* T. S. Hunt, L. E. and D., Phil. Mag. (4) xiii. 239 ; and Geology of 

 Canada, page 565. 



f For a notice, with analyses by the author, of a green hydrated silicate of 

 alumina, iron and potash, allied to glauconite, from the paleozoic rocks 

 of Canada and of the Mississippi ralley, see the Geology of Canada, 

 pages 487, 488 ; where also will be found an analysis by the author of 

 the glauconite from the Cretaceous formation of New Jersey. See also 



illiman's Journal [2], xxxiii. 277. 



