Pjrotartareous, and Pjroligneous Acids. 41 



they were thought to be different from each other, and dif- 

 ferent in their whole nature from any other vegetable acid. 



H. Characters given to the Pyromucous Acid. 



Lemery, Bocrhaave, Neumann, Cartheufer, Macquer, and 

 Bucquet, were the firft who infilled on the fpecific characters 

 of that acid which has been called the pyromucous in the 

 Methodical Nomenclature, and which had long been diftin- 

 guifhed by the name of J'pirlt of honey, of fugar, of manna, 

 of gum, &c. M. Schrikel, in giving a detailed hifiory of the 

 analyfis of ftigar and of this acid in 1776, greatly enlarged 

 and confirmed the ideas before conceived reflecting the pe- 

 culiar nature of the pyromucous acid, and all chemifts have; 

 fince adopted that opinion. It was character! fed by its dark 

 red colour when impure, and its golden yellow colour after 

 being rectified; by its odour of caramel, its very pungent 

 tafte, its volatility, nearly fimilar to that of water; by it? 

 action on the fkin, which it tinges red, and on the glafs of 

 retorts, which it feems to attack. It was believed to be en- 

 tirely contained in mucous matters, and to be only developed 

 by fire ; it was faid to be fufceptible of decompofition by 

 heat, and of being converted into gafeous bodies. But, be- 

 fides that its hippofed action on glafs depended only on the 

 adherence and penetration of the charcoal of the fugar ; he- 

 fides the proof, already well eftabliflied, of its non-exiltence 

 in faccharine and gummy matters, and of its entire produc- 

 tion by fire, it mull be allowed that, in examining what has 

 been done in regard to faline compounds and the attractions 

 of the pyromucous acid, no refult had been obtained but 

 vague and undetermined notions, which fecmed to excite 

 doubt and uncertainty in regard to the particular nature of 

 this acid. The reader will be enabled to judge of the truth 

 of this affertion by perufing, in particular, the details given 

 under the article Syrupy Acid of the Ditlionnaire de Cbimh 

 Encycloprdique, where our learned colleague Guyton has col- 

 lected every tiling then known refpecting this empyrenmatic 

 acid: when drawing up, therefore, the article in my Syftem 

 of Chemical Knowledge, written and printed feveral months 

 before the difcovery oew fubmitud to the Inititute, I wa3 

 Vol. \ 111. Ci not 



