2S0 THE CANADIAN NATURALIST. [Aug. 



following process was however attempted. The salts left by its 

 evaporation were treated with carbonate of ammonia to separate a 

 portion of silica, and then with recently precipitated carbonate of 

 silver, by which the alkaline chlorids were converted into carbonates. 

 The solution now retained in some undetermined form a portion 

 of silver, which was separated by fusing the evaporated saline resi- 

 due in a silver crucible. By a second evaporation and fusion there 

 was obtained a mixture of soda and potash, combined only with 

 carbonic, sulphuric and boric acids. By directly determining the 

 other ingredients the boric acid was estimated from the loss, and 

 was found equal to 0-028 parts in 1000 of water, which contained 

 0*752 of solid matters. The conversion into carbonate of the sul- 

 phates hi the mixed salts, by the aid of bicarbonate of baryta, would 

 simplify this process. In § 35 it has been explained that the 

 amount of carbonate of soda in the waters of the third and fourth 

 classes was generally calculated from the excess of the alkaline 

 bases, and controlled by the amount of carbonate of baryta preci- 

 pitated from chlorid of barium by the alkaline salt. It was found, 

 however, that this last method always presented a certain deficit, 

 due to the borate of soda, whose quantity in many of the waters, is 

 too large to be disregarded. The precipitate of carbonate of baryta 

 contained a portion of sparingly soluble borate of baryta, which 

 was not completely removed by long and continued washing. 



^ G-t. I have recently had an opportunity of examining from 

 California the waters of a borax lake, which contains, beside 

 borate and carbonate of soda, a portion of chlorid, and a little 

 silicate, traces only of phosphate, and no sulphate. It held in solu- 

 tion very small quantities of earthy carbonate, and was remarkable 

 for a large proportion of potash, already referred to in § 53. The 

 evaporated and fused saline residue was treated by the 

 ordinary methods for the determination of the chlorine, carbonic 

 acid and silica ; while the bases were obtained in the form of sul- 

 phates by the aid of sulphuric and hydrofluoric acids, and after- 

 wards separated as chlorids by the aid of chlorid of platinum. 

 From the data thus obtained the following ingredients were found 

 by calculation for 1,000 parts of the water : 



Carbonate of soda 9.476 



Biborate of soda - 4.395 



Chloride of sodium 1.702 



Carbonate of potash 1.818 



Silica 0.129 



17.520 



