with Observations on the Analysis of Salt-brines. l7 

 Sulphate of limCj real, . . 22 



25 -25 grains. 



Carbonate of lime, .. .. 1*2 



1-3 



2-5 2-5 



Carbonate of magnesia, .. 1*7 



2-S 



4-5 4-r> 



The two last ingiedieiits might be accidental products, from 

 the decomposition of muriate of magnesia and of lime. Mu- 

 riate of magnesia is decomposed by heat ; a portion of its acid 

 is expelled ; and the magnesia separated in consequence of this, 

 will absorb carbonic acid, from the current of warm air applied 

 during the evaporation, or from the carbonic acid gas which tlie 

 sea-water itself contains, and which is not immediately expelled 

 by heat. The small portion of carbonate of lime might be pro- 

 duced in a similar maimer, or from the action of the carbonate 

 of magnesia on muriate or sulphate of lime. I accordingly 

 found, in a suijsequent analysis, that on adding muriate of ba- 

 rytes to sea-water, no carbonate but only sulphate of barytes is 

 precipitated, which proves that these conclusions are just. For 

 the small portion, therefore, of carbonate of magnesia, the equi- 

 valent portion of muriate of magnesia, 4*2, raising it to 103'6, 

 is to be substituted. If the lime which afforded the carbonate 

 existed in the state of sulphate, then the equivalent portion of 

 this 3'4 is to be added to the sulphate actually obtained, making 

 it 28"4. If it existed in the state of muriate of lime, it still 

 would, but for this change, have been converted in the progress 

 of the evaporation into sulphate of lime ; the same substitution, 

 therefore, is in this view equally to be made. With these cor- 

 rections, and reducing the proportions to a pint, the ingredients 

 and their quantities' will l)e as follow : 



Muriate of soda, .. 182*1 grains. 



Muriate of magnesia, . , 25*9 



Sulphate of soda, . . 7"5 



Sulphate of magnesia, . . .')*9 



Sulphate of lime, .. 7*1 



226*.> 



Tlie results of the preceding analysis are different froin those 

 I had expected to obtain. I had supposed, that in Lavoisier's 

 method, the sulphate of soda, and muriate of lime, which he 



Vol. 51. No. 237. Jan. ISIS. B stated 



