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Sulphide of Allyl (Garlic Oil), C 12 H 10 S 2 . When iodide of 

 allyl is allowed to fall drop by drop into a concentrated alcoholic 

 solution of protosulphide of potassium, a very energetic action ensues, 

 the liquid becomes very hot, and an abundant crystalline deposit 

 takes place of iodide of potassium. It is important that the iodide 

 of allyl should only be added gradually to avoid spirting, hy which a 

 part of the product would be lost. As soon as the action ceases, 

 the liquid is mixed with a slight excess of sulphide of potassium ; 

 addition of water now separates a light yellowish limpid oil possess- 

 ing a strong smell of garlic. When rectified, this liquid hecomes 

 colourless, it boils at 140 C., and gives with nitrate of silver a crystal- 

 line precipitate soluble in a boiling mixture of alcohol and water, 

 and separating from this solvent in the form of beautiful white 

 needles, absolutely identical with those which the natural essence of 

 garlic produces. Sulphide of allyl also comports itself with corrosive 

 sublimate and with bichloride of platinum exactly like the natural 

 garlic oil. 



Allyl-Mercaptan, C 6 H 6 S 2 . When in the process for the prepa- 

 ration of the preceding compound the protosulphide of potassium is 

 replaced by the hydrosulphate of sulphide of potassium, a volatile 

 product is obtained, having a similar but more ethereal odour. This 

 substance acts with energy upon protoxide of mercury, with which it 

 forms a compound, dissolving iu boiling alcohol, and separating from 

 it on cooling in the form of pearly scales of remarkable brilliancy, 

 which present the greatest resemblance to the mercaptide of mercury. 

 The liquid obtained in the above-mentioned reaction boils at 90, 

 and possesses a composition and an aggregate of properties which 

 closely resemble those of the mercaptan of the ethyl-series, being, in 

 fact, the allylic mercaptan, C 6 H 6 S 2 . 



Allylamine, C 6 H 7 N. By boiling cyanate of allyl (C 8 H 5 NO 2 ) 

 with a concentrated solution of caustic potassa until the oily layer 

 entirely disappears, a complete decomposition ensues, and the residue 

 contains only a mixture of carbonate of potassium with an excess of 

 the alkaline hydrate ; the volatile products condensed in hydrochloric 

 acid furnish a saline mass which may be obtained crystalline on 

 evaporation. This substance is always a mixture, the constituents of 

 which vary both in nature and properties. The action of potassa on 

 it not only separates a base, which is readily soluble in water, but 



