T. S. Hunt on the Chemistry of Natural Waters. 205 
water. The Saratoga water, after some time, gives a feeble al- 
n two cases, however, considerable tities of silica are 
found dissolved in natural waters. The first is met with where 
the rapid solvent and sing action of heated waters 1s 
po . ; 
exerted upon alkaliferous siliceous minerals (§ 14), as seen in 
springs like the Geysers.! The second case is that of those rivers 
and streams which drain surfaces covered with decaying vegeta- 
tion and decomposing silicates, from both of which they derive 
dissolved silica. Such waters contain but small amounts of solid 
as we 
(which contains in 10,000 parts, 0°6116 of solid matters), to 
90-2060, or thirty-two per cent; while in the St. Lawrence, (which 
contains for the same amount of water, 1-6056,) the silica equals 
3700, or twenty-four per cent of the solid ingredients. The S 
analysis by H. Deville of the river-waters of France show, in : 
like manner, large amounts of silica, which seem to have been 
hitherto overlooked in the analyses of most chemists. (Ann. de 
ee. et de Phys., [3] xxiii, 32. 
appears to increase with that of the carbonate of soda. Intl 
following table the proportions of carbonate of soda and silica 
_ for 100-0 parts of solid matters are given for certain springs, 
_ whose analyses will be found in tables 111 and IV: 
11. | 10. | WT. | TW. | IL. | IIT. 
e761) 4.4 8.) & ; 
III, | II. 
I. | 5. 
9-4| 3-4| 7-0| 8-0| 9°2 (21-0 /25°0 
"6| -6| 16| 15/17 | 29] 30 
ae 
a ee ne 
Giek of sada. |... 6 | 16 
Silica “4. 4 
ee 
