16 The Natron Lake of Loonar. [no. 1, new series, 



A fresh portion of salt was dissolved, and treated by a little ni- 

 tric acid ; after effervescence and filtration, solution of nitrate of 

 baryta was added — no reaction — absent sulphuric acid. Phosphoric 

 acid being evidently in small quantity, if present at all, was not 

 looked for. The preliminary examination of each sample of salt 

 was conducted in a similar manner. 



Guided by the qualitative examination above shown, the quan- 

 titative determinations were carried out. The usual methods 

 adopted by chemists were employed throughout in these determi- 

 nations. To ascertain the constitution of the salt, some special 

 experiments were required. Frezenius and Will's method for the 

 determination of the carbonic acid was made use of, to ascertain 

 whether it was really a sesquicarbonate with the formula 2 NaO, 

 3 CO a like the natural compounds of soda and carbonic acid in 

 Africa, or whether it had the more ordinary formula of the neutral 

 or bicarbonate. These experiments showed in the case of the 

 " Dulla" salt, that there is a mixture of carbona te and sesquicar- 

 bonate, in the proportion of 54 per cent, of the neutral carbonate 

 and 30 per cent, of the sesquicarbonate ; but in the others, a neu- 

 tral constitution was found to exist, as exhibited by the formula 

 NaO, C0 2 . The point of interest connected with the constitution 

 of the Dulla salt is purely a scientific one, since rratural sesquicar- 

 bonates are very rare, having hitherto been found only in Fezzan 

 in Africa, in the soda lakes of Hungary, and in Venezuela, South 

 America ; to this list we may now however add the Locnar lake in 

 the Nizam's country. An artificial sesquicarbonate can only be 

 obtained with difficulty, and under certain conditions involving a 

 very careful employment of temperature. 



The following is a statement of the composition of the several 

 specimens of salts from the Loonar lake, calculated on 100 parts. 



No. 1. 



" Dulla." 



* 83-82 ; equal to 77-30 of neu- 



tral carbonate consisting of — 



Carbonic acid 

 Soda 



38 00 

 45-82 



31*48 of carbonic acid 

 y 45-82 of soda. 



J 



77-30 neutral carbonate an- 

 hydrous. 



