76 ORGANIC CHEMISTRY. 



Alcohol. — It is obvious that the sugar thus obtained may, by fer- 

 mentation, be converted into alcohol, or spirit of wine. In this 

 country, potatoes have been treated with sulphuric acid, in order to 

 convert their starch into sugar, from which spirit was obtained by 

 fermentation, and subsequent distillation. 



CAEBOM^. HYDROGEN. OXYGEN. 



Woody Fibre 50, 5,4 43,2 



Pyroxylic Spirit 44,53 9,16 46,31 



Alcohol 51,98 13,7 34,32 



Gum and Sugar 42,47 6,9 50,63 



Acetic Acid 46,83 6,33 46,82 



Malic Acid 40,68 5,06 54,26 



OxaUc Acid 33,222 0,244 66,534 



If for woody fibre we substitute animal fibre, or muscle, besides 

 the three elementary constituents of wood, we introduce a fourth- 

 azote ; animal fibre, or fibrin, containing 



CARBON. OXYGEN. HYDROGEN. AZOTE. 



63,36 19,685.. 7,021 19,934 



By submitting fibrin to the action of various agents, we some- 

 times obtain products similar to, but generally different from, those 

 obtained from wood under the same circumstances. Thus, fibrin is, 

 by dilute sulphuric acid, converted into sugar, and by nitric acid, 

 into oxalic acid ; but, on decomposing it by heat, instead of acetic 

 acid, that very singular alkali, ammonia, is evolved ; and till the 

 discovery of ammonia in the liquor afforded by the distillation of 

 coals in gas-works, the decomposition of animal substances, by heat, 

 was the only source from which the demands of commerce for am- 

 monia and its salts was supplied. The animal matter, generally 

 hoofs and horns, was decomposed in iron retorts. Carburetted hydro- 

 gen, water, carbonate of ammonia, and oil, passed over, while a 

 porous charcoal, having a great affinity for colouring matter, and 

 difficult to incinerate, remained in the retort. Part of the carbonate 

 of ammonia condensed in a crystalline mass on the upper part of 

 the receivers, and part dissolved in the water, and formed the harts- 

 horn of commerce. The carbonate was either purified by sublima- 

 tion, or was combined with muriatic acid, and sublimed into cakes 

 of sal ammoniac. When animal fibre is used in this process, both 

 the ammonia and the oil are formed by its decomposition, as neither 

 of them exist, as such, in fibrin. 



Prussic Acid J the most deadly poison known, might be considered 



