4,^ 0?f GANTUAKIDC$, 



Experiments and buted to the cuftom prevalent with thofe who colIe£i the Can* 

 canthwid^s! ^"^ tharides, of expofing them to the vapour of this acid ; but when 

 he found, on fubjecting fome of thefe infedts which had beetj 

 procured without the afliftance of vhiegar to experiment, that 

 they were jQmilar to tiiofe of commerce, he was obliged to re* 

 nounce his firft idea, and to endeavour to afcertain the nature 

 of the acid they offered him, by experiment. It appears that 

 bis endeavours have, in this inftance, been unfuccefsful ; for 

 he finifties by inferring that his progrefs is not fufficiently ad- 

 vanced to determine with certainty ; and that, although the 

 acid in quellion has fome analogy with the phofphoric, he, ne- 

 verthelefs, does not think that it poflefles all its properties, and, 

 confequently, is of opinion it (hould be coniidered as a peculiar 

 fpecies, until new experiments hAve fliewn that to which it 

 in reality belongs. 



The third produfl of cantharides, called by Thouvenel and 

 by Cit. Beaupoil,. green matter, does not feem to experience 

 any change from the air, at leaft in its phyfical properties. It 

 is infoluble in cold water ; it liquefies in warm water, floating 

 on its furface like an oil ; alcohol and ether diflblve it, and its 

 folution in thefe two menftrua isdecompofed by water. Oxi- 

 genated muriatic acid brought into contact with this matter, 

 and renewed from time to time, at firft feems not to have any 

 a6lion on it, but at length fmall whitifli, brilliant particles are 

 detached from it, which fall to the bottom of the veflel : in 

 lefs than a week it lofes its fmell and its colour, and becomes 

 thick and glutinous ; and notwithftanding repeated wafhings, it 

 conftantly retains the odour of the oxigenated muriatic acid. 



Diluted nitric acid, aflifted by heat, gives it a ruddy colour, 

 a rancid, penetrating odour, and alfo a confiderable confif- 

 tence. 



Cauftic foda combines with It without the aid of heat, and 

 without a difengagement of ammonia. The product of tkis 

 union is decompofed by the acids. 



Expofed to an elevated heat it fufes, and forms a liquid of an 

 oily appearance and flightly tranfparent, which, by cooling, 

 quickly refuraes the folid ftate. By a more powerful heat it is 

 decompofed, its colour changes, a yellowifh oil, very analo- 

 gous to that obtained from the diftillation of wax, and an acid 

 phlegm, pafs into tlie receivers, but not an atom of carbonate 

 of ammonia. 



With 



