T. S. Hunt on the Chemistry of Natural Waters. 191 
but their occurrence in the Paleozoic strata of the United States, 
far remote from any evidence of volcanic phenomena other than 
slightly thermal springs, shows that an action too gentle or too 
deeply-seated to manifest itself in igneous eruptions, may evolve 
carbonic acid abundantly. The sulphuric-acid springs of Western 
New York and Canada, to be described further on, are not less 
remarkable illustrations of the same fact. 
comparatively large amounts, The explanation of this is evi- 
dent: for although nitrates themselves are not directly removed 
rom the water, they are by the reducing action of organic mat- 
ters converted into ammonia, which is retained by the soil. In 
consequence of this affinity, the argillaceous strata, whether of 
the present period or of older formations, hold ina very fixed 
form a considerable quantity of nitrogen. ‘This, from the slow- 
hess with which it is eliminated in the form of ammonia under 
the influence of alkaline solutions, probably exists as an am 
moniacal silicate, (§ 6). The action of acids, however, as well 
as alkalies may be supposed to liberate it from its combination, 
and thus generate the ammoniacal salts which are such frequent 
stones of former geological periods, in quantities scarcely inferior 
i n times, amounting for 
v 
S 
> 
B 
oD 
ee 
i=) 
a, 
B. 
‘o 
“" 
jor) 
oO 
se, 
9 
ce) 
5 
amount of this element thus retained in the rocky strata of the 
earth’s crust is very great.” 
: If we attempt a chemical classification of natural waters 
M accordance with the principles laid down in the preceding 
Sections they may be considered under the following heads: 
: Atmospheric waters. 
yy ters impregnated with the soluble products of vegetable decay. 
C. Waters impregnated with the salts from decomposing feldspathic 
rocks, and holding a portion of carbonate of soda as a characteristic 
Ingredient, : 
D. Waters holding neutral salts of sodium, calcium or magnesium from 
Strata where they existed as solid salts, or as impregnating brines. 
tars ihe mea cat 3 ee aL 
Ww 
~ Ann. des Mines 5 iii, 151-523. 
a: For an ex ona a Mer A put forward in the four preceding sections, see 
Paper in the Canadian Journal for 1858, p. 206. 
