402 A Memoir on the Uric Acid. 
alkaline taste, and is decomposed by all 
acids. Even the carbonic acid and» the 
alkaline carbonates occasion a white preci- 
pitate from it. The nature of this precipitate 
differs, however, according to the circum- 
stances under which it has taken place. If 
‘the alkaline solution be poured) into diluted 
muriatic, sulphuric, or any other strong acid; 
or if these acids be employed in any: way, 
provided their quantity exceeds what is  ne- 
cessary to saturate the alkali, uric acid is 
precipitated in a pure state. But if the 
precipitating acid, on the contrary, be gra- 
dually added to the alkaline solution, and. in 
a quantity insufficient for its saturation,’ the 
precipitate is, either wholly or in part, an 
insoluble compound of uric acid and alkali. 
This saturated compound of uric acid. and 
alkali is alone thrown down by solution of | 
carbonate of ammonia, and by carbonic 
acid.* The alkaline solution may, therefore, 
be regarded as consisting of a neutral com- 
pound of uric acid and alkali, dissolved by 
an excess of the latter substance... To obtain 
the saturated compound, we may either, di- 
rectly combine the uric acid with the alkali, 
* This fact escaped the observation of Scheele, whose 
sagacity and accuracy on most occasions are singulatly 
conspicuous, “See ‘his 9th Essay, § 4. 
