2 1 2 Mons, R. Piria on the Combinations of Salicyle, 
Radical (14 C d" 5 H). Oxygen. 
1 2 = benzoyl. 
1 3 anhydrous benzoic acid. 
1 ^ salicyle. 
1 5 anhydrous salicic acid. 
Hydruret of Salicyle, 
This substance when pure is colourless, but when impure is 
deep red, possessing an agreeable and aromatic odour, to a 
certain extent resembling that of the oil of bitter almonds : 
by distillation it is rendered completely colourless, by expo- 
sure to air it again acquires a reddish hue. Digested with 
water a small quantity is dissolved, sufficient however to cause 
the latter fluid to acquire its odour ; its taste is very pungent 
and acrid, like that of most essential oils. It is without action 
on litmus paper. Placed in contact with the salts of the ses- 
qui-oxide of iron it assumes a splendid violet colour, which 
by exposure to air becomes yellow. The salts of the protox- 
ide of iron do not exert any manifest action upon it. In 
aether and alcohol it is soluble in all proportions : w^ater pre- 
cipitates it from its alcoholic solutions. Its specific gra- 
vity at 56° Fahr. is 1*1731 : it boils at a temperature of about 
400°. Mixed with alkaline carbonates it slowly decomposes 
them, causing the evolution of their acid ; upon the applica- 
tion of heat this action becomes much more energetic. Cau- 
stic alkalies combine with it, producing a considerable disen- 
gagement of heat. Chlorine and bromine combine with the 
base of the hydruret, producing chloride and bromide of 
salicyle, disengaging hydrochloric and hydrobromic acids; 
iodine dissolves in the hydruret without suffering any obvious 
change. 
Digested in nitric acid, hydruret of salicyle is converted 
into a substance termed nitro^salicide, which becomes, by 
continuing the digestion, changed into carbazatic acid. 
The hydruret of salicyle may be readily prepared by the 
following process. Dissolve four parts of bichromate of 
potass in a sufficient quantity of water, and add three parts 
of strong sulphuric acid. Then dissolve some salicine in six 
parts of hot water, place the solution in a retort, and raise it 
to the boiling temperature. Adapt a carefully cooled re- 
ceiver, and through the tubulure of the retort add, by small 
quantities at a time, the acid solution of bichromate ol potass 
to the hot fluid; violent action ensues; the mixture turns 
green from the formation of green sulphate of chromium, and 
a milky fluid distils over. The products of this distillation 
by repose deposit salicyle in the form of oily drops. These 
