STORAX. 245 
the filtrate with cold petroleum spirit. One half of the liquid is 
then distilled off, and the solution filtered from the precipitate, 
which consists of the ethyl cinnamate and a portion of the sty- 
racin. The clear liquid deposits the styracin on standing, in 
dazzling white fascicular crystals, which melt at 44°. 
Styrolene, CsH,, formerly called Styrol or Cinnamol, is chemi- 
cally phenyl ethylene. It is a volatile oil, and was formerly 
obtained by distilling liquid storax with water, to which sodium 
carbonate was added to prevent any cinnamic acid passing over ; 
it is strongly refractive, colourless, very aromatic, boils at 144°°5 
and has a sp. gr. of 0°925 at O°. The amount of styrolene present 
varies according to the age of the balsam, also by reason of the 
varying methods employed to extract the balsam. On oxidation 
it yields benzoic acid. When styrolene is heated for some time to 
100° or for a short time to 200°, it is converted without changing 
its composition into Meta-styrolene, a vitreous, strongly refractive 
mass, insoluble either in alcohol or ether. Its sp. gr. is 1:054, and 
it is too hard to be cut with a knife. 
When cinnamic acid is distilled with four times its weight of 
baryta, a body is formed which has been considered identical with 
styrolene*, and Hempel found that a similar hydrocarbon is 
formed when the vapour of cinnamic acid is passed through a red- 
hot tube, as well as by the distillation of copper cinnamate +, and 
the slow distillation of free cinnamic acid. 
Styrolene has been obtained in other ways. Botsch found that 
when Dragon’s blood is distilled with zine dust, 66 per cent. of 
styrolene are formed, in addition to ethylbenzene, a little toluene, 
and a smailer quantity of higher boiling substance {. Berthelot 
obtained it, together with benzene and other hydrocarbons, by 
heating acetylene to the softening point of glass §, and by passing 
a mixture of ethylene and benzene through a red-hot tube ||; he 
also discovered it in coal-tar 4. 
Styrolene is now obtained by the slow distillation of cimnamic 
acid, which is manufactured synthetically on the large scale (see 
Cinnamon). When cinnamic acid is allowed to stand for some 
* Compt. Rend. xxi. p. 1376. + Ibid. lix. p. 316. 
{ Monatshefte f. chem. 1. p. 609. 
§ Ann. Chem. Pharm. exli. p. 181. 
|| Ibid. exlii. p. 257. 4 Ibid. Suppl. ii. p. 368. 
