on Phosphoric Acid. 11 
of the various superphosphates of lime much 
farther. 
I procured a test superphosphate of lime, 
or one of such strength that 100 measures of 
it would neutralize as much lime water as 
100 measures of my test sulphuric and other 
acids. Its specific gravity was, 1,115; of 
course it must contain 113 per cent, phospho- 
ric acid, capable of being united to any base, 
and 2 or 3 phosphate of lime. 
There is a salt now considerably used both 
in medicine and chemistry, called phosphate 
of soda, which is prepared from superphos- 
phate of lime and soda, I was desirous to 
ascertain the proportions of the elements of 
this salt in the first instance, as it was likely 
to be an useful agent in the formation of 
other salts. Into 200measures of £ test carb. 
soda of 1.11 sp. gr.I dropped by degrees 200 
measures of the test superphosphate of lime, 
a_brisk effervescence ensued after each portion 
and due agitation, which effervescence did not 
terminate till the whole 200 measures had 
‘been added. About 7 grains phosphate of 
lime were thrown down and the liquid pos- 
sessed all the characters of a solution of 
phosphate of soda. It contained 23 phos-. 
phoric acid and 14 soda; consequently the 
