of Cantkarides. 147 



4th, A parenchymatous matter. 



Similar products were obtained by C. Beaupoll ; but, in- 

 stead of being satisfied with ascertaining their existence, he 

 examined them separately ; and in this consists the chief 

 difference between his labour and that of Thouvenel. 



He first remarked, that the aqueous solution of the kind 

 of extractive matter furnished by cantharides soon experi- 

 enced a sort of alteration when exposed to the air ; that thfe 

 liquor became turbid, formed a yellow precipitate which 

 acquired a peculiar odour, became covered with a viscid 

 pellicle which emitted a foetid ammoniacal odour ; and that 

 when it arrived at this term the same liquor exhibited no 

 longer any sensible change. He then remarked that the 

 solution in question, before it experienced all the changes 

 occasioned m it by exposure to the air, gave a strong red 

 colour to tincture of turnsole ; that when mixed with rcc- 

 lilled alcohol, or with ether, it divided itself into two parts 

 nearly equal, one under the form of a black glutinous pre- 

 cipitate insoluble in alcohol, and the other under that of a 

 yellow ish brown matter exceedino-ly soluble in alcohol. 



He aseej'tained also that the black precipitate dried readily 

 in the air, became brittle and friable, and reddened, tincture 

 of turnsole ; that it combined very well with potash, suffer- 

 ing to be diseniraged ammonia : that when distilled over an 

 open fire it swelled up and gave an acid liqusH", a thick oil 

 and carbonate of ammonia, cUid that it left \h the retort a 

 drv, brittle, and friable charcoal. 



I'rocecding then to examine the yellow matter which re- 

 mained in solution in the alcohol, C. Beaupoil asserts, that 

 when it is concentrated by the evaporation of its solvent, 

 it retains the same odour and the same savour as the ex- 

 tract; that it dissolves completely in water, and reddens 

 tincture of turnsole ; that it combines wholly w^ith potash 

 without any disengagement of ammonia; and that this 

 combination results from a homogeneous and glutinous 

 body soluble in water, and capable of being precipitated by 

 a weak acid ; and, in the last place, that when distilled over 

 an open fire it swells up very little, gives an acid liquor, a 

 black fuetid oil, and carbonate of ammonia; but that all these 

 products are in general less abundant than those obtained 

 from the black precipitate. 



Of these different results the author thought it his duty 

 • to attend more particularly to the acid, which, as seen, is so 

 easily observed in the infusion of cantharides, or in the ex- 

 tract which they furnish. 



He at first supposed that this acid was analogous to that 

 K 2 ot 



