1816.] Analysis of native Caustic Lime. 3 



The precipitate, when well washed and dried, weighed 0*95 

 of a grain. It was soluble in sulphuric acid, and possessed 

 the properties of alumina. 



Diluted sulphuric acid was added to the solid matter not 

 acted upon by the potash ; the whole boiled for some time, 

 and then filtered. The sulphate of lime obtained weighed, 

 after being heated red, 136 grains, which, estimating the lime 

 at 43 per cent., is equivalent to 58*48 grains of lime. 



The sulphuric solution was precipitated by ammonia, and 

 two grains of oxide of iron were obtained. 



Supposing the quantity of water in every part of the piece 

 first taken to be uniform, it would follow that the 188 grains 

 contained 117*05 of water; so that 70*95 was the quantity of 

 dry matter acted upon. The results were 



Silica . . . 

 Alumina . 

 Lime . . . 

 Oxide of iron . 



68-93 



The loss is therefore rather more than two grains, which may, 

 perhaps, actually have taken place, and the difference may 

 have been derived from the unequal diffusion of water through- 

 out the piece. 



Supposing 100 parts of the specimen to have been taken, 

 the analysis will stand thus : 



Grains. 



Lime . . . 82-424 



Silex . . . 10*570 



Iron . . . 2-820 



Alumina . . 1-.340 



Loss . . . 2-846 



100-000 



It is perhaps worthy of observation, that during the solu- 

 tion of the substance in muriatic acid, a part only of the silica 

 separated; the greater part remained in solution until heat 

 was applied, when it gelatinized, as in the case where it is sepa- 

 rated by an acid and heat from its combination with alkali. 



