306 On Analyzing Lime. 



The characters of this limestone, which answers to 

 the magnesian limestone, are its extreme hardness ; 

 striking fire with steel, in consequence of which it must 

 contain a large proportion of silica ; slow solubility in 

 muriatic acid, 8icc. 



The solution, when effected in muriatic acid, was 

 tested with carbonate of potash after filtering it, which 

 produced a copious precipitate. 



Oxalate of potash, added in a similar manner, also 

 produced a precipitate. 



The last experiment decided the presence of lime, 

 and the former in a great measure, the existence of 

 magnesia. To ascertain this fact, however, with more 

 certainty, a portion of the solution was examined with 

 carbonate of ammonia, and the precipitate formed, was 

 separated. The filtered liquor was now examined with 

 phosphate of soda, which occasioned a copious preci- 

 pitate. The quantity of this appeared to equal the quan- 

 tity obtained by oxalate of potash in the former experi- 

 ment, or that caused by the carbonate of ammonia im- 

 mediately preceding. On examining the precipitate 

 formed by carbonate of ammonia with muriatic acid 

 and oxalate of potash, the whole w^as discovered to be 

 carbonate of lime. 



The phosphated soda, according to Dr. Wollaston, 

 added after the carbonate of ammonia, in the manner 

 pf which I have spoken, (when the carbonate is used in 

 the common temperature of the atmosphere) is the most 

 accurate test for the discovery of magnesia. 



The experiment for determining the presence of 

 magnesia was made in a general way, in fact, merely to 



