and some of the products of its decomposition. 113 



diately at that of 200° C. Intensity and duration * of actioi^; 

 are seen here, as everywhere else in nature, to be equivalent.:- 



Light appears, however, to play a part in the transforma- 

 tion of styrole ; at least a small portion sent to Professor Lie- 

 big five years ago by E. Simon, and which had been kept in a 

 dark press, is still as fluid as if newly distilled. 



This metamorphosis of styrole by heat is so much the 

 more extraordinary, as this agent generally acts in a contrary 

 direction, either to liquif}' or volatilize. The white of egg 

 alone, in certain points, offers some analogy ; and these two 

 bodies, at a higher temperature, exhibit likewise, though in a 

 distant degree, the same behaviour. 



L. Gmeiin t has shown that the coagulated white of egg, 

 heated in a Papin's digester with water to 200° C, becomes 

 again fluid, and forms with the water a yellow liquid. This 

 observation has been lately confirmed by Wohler and 

 Vogel J. 



If metastyrole is heated in a small retort over a spirit- 

 lamp, it becomes again fluid, and a colourless oil distils over, 

 which is pure styrole. By a carefully conducted distillation 

 there remains scarcely any residue in the retort. 



It was possible that the oil obtained by distilling meta- 

 styrole might be another body of the same composition as 

 styrole and metastyrole, but possessing different properties. 

 The regenerated oil forms instantaneously with bromine the 

 characteristic smelling bromine compound. Besides this re- 

 action, which, as will be seen immediately, is not decisive, the 

 action of heat on the regenerated oil is quite conclusive. 

 Heated to 200° C, in a tube hermetically sealed, it is con- 

 verted into metastyrole, which by a higher temperature is 

 again in its turn reconverted into styrole. 



After having ascertained that styrole and metastyrole had 

 the same composition per cent., and that the difference in their 

 physical properties could only arise from a dissimilar arrange- 

 ment of their molecules, it was of some interest to obtain an 

 explanation of this arrangement. As the specific weight of 

 the vapours of both bodies could not be compared with each 

 other, there remained no other resource but to study more 

 closely the products of decomposition of metastyrole. As 

 bromine and chlorine act only very slowly on metastyrole, 

 sulphuric acid carbonizes it, and by fusing with potash a sim- 



* The varying amount of styrole obtained from the different sorts of 

 storax is probalily owing to the same metamorphosis produced in the 

 conrse of time. 



t Handbiich, 3rd edition, vol. ii. p. 1053. 



X Ann, dcr Chem. und Pkarm., vol, xli. p, 238. 



PhiL Mag. S. 3. Vol. 27. No. 178. August 184.5. I 



