Hth '^'''&t^:B\yih^t\A Hofmann on Styrole, 



In this operation a peculiar phaenomenon is observed, which 

 was first indicated by Simon. When styrole is heated 

 in a tubulated retort in which a thermometer is placed, a 

 quantity of vapour is evolved at 100° to 120° C. At 145|° 

 the fluid begins to boil, and there distils over a clear, oily and 

 beautifully iridescent fluid. For some time the thermometer 

 remains stationary at the above temperature, then begins sud- 

 denly to rise so fast, that it must quickly be removed from 

 the retort. The portion left behind has now completely 

 changed its character to a thick, tenacious substance, through 

 which the bubbles formed at the bottom of the vessel force 

 their way with much difficulty to the surface. From this pe- 

 riod scarcely any more oil distils over, and, on allowing the 

 retort to cool, its contents become a solid transparent glass. 

 The quantity of this solid residue is variable: it amounts 

 sometimes to a third of the oil employed. We shall return 

 to this point afterwards. The product of the distillation is 

 perfectly pure styrole. 



2. Properties of Styrole. — This body is in the form of a 

 colourless, transparent fluid, of a burning taste and peculiar 

 aromatic odour, resembling a mixture of benzole and naphtha- 

 line, which adhei-es tenaciously to linen. At a temperature 

 of 20° C. it neither solidifies nor loses any of its extreme mo- 

 bility. Exposed however to a mixture of solid carbonic acid 

 and aether, it solidifies instantaneously into a beautiful white 

 crystalline mass. It is in the highest degree volatile, and eva- 

 porates at all temperatures ; the oily spots made by it on paper 

 disappear after a few seconds. The boiling-point lies, as 

 already stated, about 1451° C. This same temperature was 

 found in several trials. A wick dipped in styrole burns with 

 a brilliant, smoky flame. Its vapour can be passed without 

 decomposition through a red-hot tube. 



Styrole is lighter than water : its specific gravity at the or- 

 dinary temperature of summer is 0'924. It disperses and re- 

 fracts the rays of light in the highest degree. Its coefficient 

 of refraction is for the red rays 1*532. 



It mixes in all proportions with asther and absolute alco- 

 hol. Spirit of wine dissolves less according to the propor- 

 tion of water it contains. It is soluble in pyroxylic spirit, 

 acetone, bisulphuret of carbon, fat and aethereal oils. Water 

 dissolves only a small proportion, but still sufficient to give 

 it the burning taste and odour of the oil. The amount of 

 water which can become mixed with the oil is equally small. 



Styrole shows no reaction on vegetable colours. Like the 

 aethereal oils, it dissolves by the aid of heat a large proportion 

 of sulphur, which, on cooling, is deposited in the form of large 



