2 1 2 Mons. R. Piria on the Combinations of Salicyle. 



Radical (14 C + 5 H). Oxygen. 



1 2 = benzoyl. 



1 3 anhydrous benzoic acid. 



1 4< 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 rny manifest action upon it. In 

 aether and alcohol it is soluble in all proportions : water 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 of potass 

 lo 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 



