1865.] CHEMISTRY OF NATURAL WATERS. 177 



vations on the silica and organic matters of this river-water will 

 be given in part III. It will be observed that in the above table 

 the figures given for the first five waters are for 1000 parts, while 

 those of the Ottawa are for 10,000 parts. 



§ 46. In this connection may be given the analyses of two 

 similar springs from Vermont, — the Highgate and Alburg springs. 

 The waters were sent me in October and November 1861, and the 

 results have already appeared in " Geology of Vermont," ii, 926. 

 Both of these waters, when examined, were slightly sulphurous, 

 and yielded the reactions of boric acid. The amount of carbonate 

 of soda was estimated from the carbonate of baryta obtained by 

 the process already mentioned in § 35. 



Highgate. Alburg. 



Chlorid of sodium , . . . £ .402 r 140 



Sulphate of soda 042 024 



Carbonate of soda 235 230 



" lime 024 036 



" magnesia 010 022 



Potash and borates undet undet. 



In 1000 parts , 713 -452 



§ 47. On the 5th January 1865, after a lapse of more than 

 seventeen years, I again visited the three springs of Caledonia 

 whose analyses have been given in the table §43, and collected 

 their waters for a second examination. The results of my recent 

 analyses show that considerable changes have occurred in 

 the composition of each of these springs, and tend to confirm in 

 an unexpected manner, the theory which I long since put forward, — 

 that the waters of the second and third classes owe their origin to 

 the mingling of saline waters of the first class with alkaline 

 waters of the fourth class. It will be observed that the three 

 Caledonia waters in 1847 were all., alkaline, though the propor- 

 tions of the carbonate of soda were unlike. Sulphates were 

 also present in all of them, though most abundant in the Sulphur 

 spring, which, although holding the smallest amount of solid mat- 

 ters, was the most alkaline. In January 1865, however, the first 

 and second of these waters had ceased to be alkaline, and con- 

 tained, instead of carbonate of soda, small quantities of earthy 

 chlorid, causing them to enter into the second class. They no 

 longer contained any sulphates, but, on the contrary, portions of 

 baryta and strontia. Only the Sulphur spring, which in 1847 

 contained the largest proportion of carbonate of soda and of sul- 



Yol. II. m No. 3. 



