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, &c. 
The solution, when effected in muriatic acid, was 
tested with carbonate of potash after filtering it, “i 
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 was discovered to be 
carbonate of lime. 
The phosphated soda, according to Dr. Wollaston, 
added after the carbonate of ammonia, in the manner 
of which Ihave 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 ina general way, in fact, merely to 
