158 Miscellaneous Intelligence. 



disappears, and a yellow one succeeds. If into the first solu- 

 tion, milk of lime, very finely mixed, be introduced, the lime 

 dissolves, but on approaching the point of saturation, a red 

 crystalline and brilliant substance is deposited. The same milk 

 of lime, put into the second solution, or that to which nitric 

 acid has been added, produces the deposition of a white or pale 

 yellow substance, also crystallized, and of a brilliant appear- 

 ance. This last substance is a combination of the lime with 

 the new acid, formed by the action of the nitric on the uric 

 acid. The first is a similar combination, containing a certain 

 quantity of colouring matter, formed also at the expense of the 

 uric acid. 



After purifying this salt by repeated crystallizations, I de- 

 composed it by a sufficient quantity of oxalic acid, and ob- 

 tained the new acid in its pure state. It is white, fusible, of 

 an acid taste, readily soluble in water and alcohol, saturating 

 but small quantities of bases, and giving, when decomposed by 

 heat, hydrocyanate and carbonate of ammonia, empyreumatic 

 oil, and charcoal. It causes white precipitates with the acetate 

 of lead, muriate of tin, and nitrate of mercury ; but it does 

 not precipitate nitrate of silver, nor does its saline combination 

 aft'ect that test. Dissolved in nitric acid, and evaporated to dry- 

 ness, it does not produce a red colour. 



The combination of the calculous acid with lime does not 

 precipitate solution of silver, but the same combination united 

 to colouring matter precipitates the salt of silver of a fine 

 purple colour. I took advantage of this property to separate 

 the colouring matter from the acid, I mixed a coloured solution 

 with nitrate of silver, until no further precipitate was formed ; it 

 was of the finest purple, and as soon as it had fallen, and 

 the fluid become clear, they were separated, and the deposit 

 washed several times; being afterwards mixed with a small 

 quantity of water, it was decomposed by the necessary quantity 

 of hydro-chloric acid. The colouring matter thus precipitated 

 by the silver, the acid to which it was united was found in 

 the fluid ; for, on adding to it a little lime, a white precipitate 

 was formed, being the combination with silver. 



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