372 Miscellaneous Intelligence. 



The flocculent matter, collected on a filter, has, at first, the 

 appearance of gelatine : on drying, it cracks, and may easily 

 be reduced to powder. It is white and insipid, insoluble in 

 potash, dissolving readily in acids, and separated from them by 

 alkalis. Their solution in nitric acid does not occasion any 

 reddening. Acids holding it in solution are tinged greenish 

 blue or light blue by ferro-prussiate of potash ; and, after some 

 time, flocculi of the sa<rie colour separate ; and the fluid re- 

 mains yellow. If distilled vinegar is used, this effect is but 

 slowly produced. 



After what has been said, it must appear singular, that the 

 flocculent matter can form with acids a combination insoluble 

 in acids themselves, but which was ascertained by Berzelius. 

 Having prepared uric acid, and washed it on a filter with mu- 

 riatic acid, the latter passed in a very turbid state, which, on 

 remaining at rest for some time, deposited a matter, that, when 

 dissolved in hot water, and treated with alkali, gave the white 

 flocculi, and the aqueous solution was coloured light blue by 

 ferro-prussiate of potash. The turbid muriatic acid became 

 transparent, and of a bright green colour, when boiled. 



It appears, from various indications, that the colouring mat- 

 ter is the same as that which tinges the urine, and the floc- 

 culent substance does not seem to differ from that of a similar 

 aspect which is deposited in the same fluid, upon its remaining 

 some time at rest. The yellow colour of uric acid calculi is 

 exactly the same with the yellow tint of urine, and, as a few 

 drops of nitric acid will give the latter a rose tint, so also will 

 they have the same effect on a solution of the above-mentioned 

 substance in the acid muriate of potash. As to the flocculent 

 matter of urine, its solution in acids is also decomposed by 

 alkalis, and it acquires a fine blue tint, when tested by ferro- 

 prussiate of potash. 



The following conclusions may be drawn from the above 

 observations. They enable uric acid to be obtained of a great 

 degree of purity, which is done by boiling it in muriatic acid. 



They explain why, in the preparation of erithric acid, a 

 liquid is obtained, which, though abounding with the acid, 



