M. Carius on Phenose. 453 



Phenose is obtained as a feebly- coloured amorphous mass 

 which deliquesces in the air ; it tastes sweet like grape-sugar, 

 with a sharp after-taste. It is soluble in water and alcohol, but 

 not in ether. When heated it becomes brown, and above 100° 

 it decomposes with the formation of a caramel odour. 



Heated either with acids or alkalies, it is rapidly changed into 

 humus-like bodies. The latter form also an acid, which seems to 

 correspond to the glucic acid which is formed from grape-sugar. 

 On account of its ready changeability by alkalies, metallic com- 

 pounds are very difficult to obtain. The lead-compound has the 

 formula € 6 H 6 Pb 3 6 . 



Phenose is as readily oxidized as grape-sugar ; the only product 

 of the action of dilute nitric acid at a gentle heat is oxalic acid. 

 Like grape-sugar, phenose prevents the precipitation of oxide of 

 copper by caustic potash. Unlike grape-sugar, however, it ap- 

 pears incapable of fermentation. 



Phenose is to be regarded as a six-acid alcohol, standing to 

 benzole in a relation analogous to that which glycol bears to 

 ethylene. 



In order to obtain the acid above mentioned as a product of 

 the decomposition of trichlorhydrine by alkalies, it is best to 

 dissolve the trichlorhydrine in alcohol and add baryta- water in 

 sufficient quantity, and heat on the water-bath for some hours ; 

 the excess of baryta is precipitated by carbonic acid, and the fil- 

 trate evaporated to a small volume. On the addition of hydro- 

 chloric acid to the concentrated liquid, almost the whole of the 

 acid is separated ; the filtered liquid, if shaken with ether, gives 

 up the rest ; both portions have to be purified by recrystallization. 



The formation of this new acid (benzenic acid) takes place in 

 accordance with the following equation, 



€ 6 H 9 Cl 3 3 + 3BaHO=3BaCl + 4H 2 + G 6 H 4 9 2 . 



Benzenic acid. 



This new acid has been named benzenic acid to indicate its 

 formation from benzole. It crystallizes in very thin colourless 

 nacreous laminse. It melts at 110° to a colourless liquid, which 

 distils over at 235°. It sublimes partly at 100°, and distils over 

 with aqueous vapour, as does benzoic acid. In solution it has a 

 strong acid reaction, and it forms well-defined salts which have 

 great similarity to those of benzoic acid. Pentachloride of 

 phosphorus produces with it a chloride which gives with water 

 benzenic and hydrochloric acids. 



When benzenate of barium is heated with soda-lime, the 

 benzenic acid decomposes in the same way as benzoic acid ; a 

 colourless very volatile hydrocarbon distils off without any dis-. 



Phil Mag. S. 4. Vol. 31. No. 211,. Jme 1866. 2 H 



