1 54 Intelligence and Miscellaneous Articles. 



first converted into nitrocinnamic acid, then into benzoic acid, and 

 finally into nitrobenzoic acid. 



Cinnamic and benzoic sethers are both, though with great diffi- 

 culty, converted into nitrocinnamic acid and nitrobenzoic aether. 

 There is almost always a great part of the sether decomposed, and 

 the acids are set free. 



Nitrobenzoic sether is solid, colourless, and of an aromatic odour 

 and taste. It crystallizes in fine rhombic lamina;. Its melting-point 

 is 11 6°, and its boiling-point 664°. It is easily obtained by exposing 

 an alcoholic solution of nitrobenzoic acid to a current of hydrochloric 

 acid gas. Its formula is C* (H« N^ O*) 03 + C* H'oOrrC's H'^ N^ O^. 



Nitrocinnamic acid dissolved in an alcoholic solution of sulphuret 

 of ammonia is reduced with the assistance of a gentle heat. Sulphur 

 is deposited, and two distinct substances are formed, one of which is 

 of a yellowish colour and belongs to the class of resins, and the other 

 to that of alkaloids. The latter is solid, colourless, crystallizes in 

 small indistinct masses, insoluble in water, soluble in alcohol and 

 in aether, and forms difficultly crystallizable salts. 



Resin a, C^^ H^s O^. This substance is brown, translucent, brittle 

 when cold ; its powder agglomerates at 59° F. and fuses perfectly at 

 140° F. Concentrated sulphuric acid imparts a purple colour to it. 

 When dissolved in potash and exposed to the air, it is readily oxi- 

 dized, and is converted into resin /3. By dry distillation it yields 

 benzoen and benzoic acid. It dissolves readily in alcohol and in 

 aether. 



Resin jd, C's H^° O^ Colour dull brownish-yellow, without taste or 

 smell, slightly fusible (above 212° F.), but little soluble in alcohol 

 or ajther. It is less alterable than the preceding resin. Sulphuric 

 acid renders it of a violet colour ; potash dissolves it with a brown 

 colour. 



The mixture of the two resins treated with nitric acid yields, as 

 gaseous products, carbonic acid, nitrous vapours and nitric oxide ; 

 as volatile products, hydruret of benzule, hydrocyanic acid, and a 

 little benzoic acid ; as residue, a flocculent yellowish substance, 

 which is benzoic acid intimately combined with a yellow colouring 

 matter of a resinous nature, which destroys its crystallizing power, 

 and accompanies it in all its combinations, even in that of aether. 

 By the action of heat, especially by distillation, the resinous matter 

 is destroyed, and perfectly pure benzoic acidis obtained. The resin 

 yields nearly one-third of its weight of benzoic acid. 



As to the constitution of balsam of Tolu, it seems very simple. 

 Primarily it is formed of the soft resinous matter C^'^ H^s O'', or of 

 that which gives rise to it. This resin, under the influence of the 

 air, is converted into cinnamic acid and resin /3 : C^^ H38 + 0^=C'8 

 H'" O^ + C'sH^oO^-fH'^O. In fact it is observed that in time 

 balsam of Tolu becomes hard, and contains a larger quantity of cin- 

 namic acid. The resin C'^ W^ O* may itself easily furnish benzoic 

 acid for C'sH^o 0^=0'^ Hi^O^ + H^ O + C* H^ The carburetted 

 hydrogen perhaps gives rise to tolene ; but it is more probable that 

 it is converted by the action of oxidizing bodies into resinous colour- 



