Mr. De la Rue on Cochineal. 493 



I. -4698 grm. of substance (a) dried at 100° C. and decom- 

 posed by nitric acid and the silver precipitated by the addi- 

 tion of hydrochloric acid, gave -2675 grra. chloride of silver. 



II. -5085 grm. of substance {b) dried at 100° C. gave 

 •2892 grm. chloride of silver. 



III. -8184 grm. of substance («) dried at 100° C. and 

 Tjurnt with oxide of copper, gave -5700 grm. carbonic acid 

 and -0554 grm. water. 



Corresponding to the following per-centage quantities : — 



I. II. III. 



Carbon ... 18-99 



Hydrogen ... 0*75 



Oxide of silver . . . 46-03 45-97 



and agreeing closely with the following formula, 



C,6H3N3 0,s+2AgO, 



Nitrococcusate of Copper. — This was made by dissolving 

 carbonate of copper in nitrococcusic acid and deposited on 

 evaporation in pale apple-green needles. I made no analysis 

 of this salt. 



The following is a synoptical table of the analyses of nitro- 

 coccusic acid and its compounds : — 



Hydrate of nitrococcusic acid . C,gH3N30i(. + 2HO. 



Hydrate of nitrococcusic acidn 4_oTTn ■ oA 



as crystallized from water j "i 4- 



Nitrococcusate of potash +2KO. 



Nitrococcusate of ammonia +2NH40 + Aq. 



Nitrococcusate of baryta +2BaO + 2Aq. 



Nitrococcusate of silver +2AgO. 



The properties of nitrococcusic acid and its salts exhibit a 

 great analogy with those of a number of acids obtained by 

 the action of nitric acid on organic bodies, more especially 

 nitropicric and styphnic acids, from which it differs by the 

 greater solubility of its salts. 



If we assume with many chemists the nitrogen of these 



