1865.] CHEMISTRY OF NATURAL WATERS. 287 



The potassium, as above determined, equals 11.46 per cent, of the 

 bases weighed as chlorids ; another trial gave 11.41. Although 

 for convenience we have represented the potassium as carbonate, 

 it will be seen that the amount of chlorine is such that it might, 

 for the greater part, have been represented as chlorid of potassium, 

 with an equivalent portion additional of carbonate of soda. 



§ 65. Carbonates. — In describing in § 43 the alkaline-saline 

 waters of Caledonia it has been shown that these contained a 

 quantity of carbonic acid insufficient to form bicarbonates with the 

 carbonated bases present. It was partly with this fact in view 

 that, after an interval of more than seventeen years, I undertook 

 the new analyses of these waters, which in § 47 are given side by 

 side with the earlier results. In these recent analyses, as there 

 remarked, a slight excess of carbonic acid was met with. In the 

 interval the springs had undergone changes in composition, and 

 while the third one still retained in a slight degree its alkaline 

 character, the other two had become waters of the second class, 

 holding instead of carbonate and sulphate of soda, chlorid of mag- 

 nesium, and baryta salts. The amount of carbonic acid had how- 

 ever undergone but little change ; and as will be seen by compar - 

 ing the figures below with those in the table in § 47, the slight 

 diminution in the first and third corresponds very closely with the 

 falling off in the amount of solid matters between 1847 and 1865 ; 

 while, on the contrary, the augmentation in the amount of carbonic 

 acid in the second is accompanied with a corresponding increase in 

 the amount of fixed matters present. 



CARBONIC ACID IN ONE LITRE OF THE CALEDONIA WATERS. 



1847. 1865. 



Gas spring 705 gram. .671 gram. 



Saline spring. 648" .66-4" 



Sulphur spring 590" .573" 



While the amounts of fixed matters and of carbonic acid in the 

 several waters have undergone but little change, we find, however, 

 that there has been a great diminution in the proportion of car- 

 bonated bases. Thus in the Gas spring in 1847 the carbonic acid 

 required for the neutral carbonates found in the analysis was .356, 

 while for the same water in 1865 only .278 of carbonic acid was 

 required. In the Sulphur spring, in like manner, the neutral 

 carbonates required .449*. or more than three-fourths of 



* By mistake this is printed .349 in § 43. 



