454 M. Berthelot on Polymers of Acetylene. 



and assumes that in benzole the free affinities of the acetylene 

 are satisfied as readily by 2 (G 2 H 2 ) as in hydride of ethyle by 

 2(H 2 ). 



The crude product from which the benzole was obtained by frac- 

 tional distillation began to boil even at 50° C, and furnished an 

 extremely mobile, very volatile liquid hydrocarbon of penetrating 

 .alliaceous odour, which was absorbed by concentrated sulphuric 

 acid and immediately decomposed. This body, which is probably 

 diacetylene, € 4 H 4 , was not obtained in sufficient quantities for 

 closer investigation. 



After the benzole had passed over in the fractional distillation, 

 the temperature rose to 135° C, and at 160° C. a liquid passed 

 over which by its reactions was identified as styrole, or tetracety- 

 lene, G 8 H 8 =4G 2 H 2 . About one-fifth of the entire quantity 

 consisted of this substance. When treated with solution of iodine 

 in iodide of potassium beautiful crystals of iodide of styrole were 

 formed, which in the course of an hour decomposed spontane- 

 ously, with separation of iodine, into a polymer of styrole, — a 

 property not possessed by any other hydrocarbon. 



After separating the styrole, the thermometer rapidly rose to 

 210° C. ; and at 250° a product passed over which remained 

 liquid, but in a freezing-mixture deposited crystals of naphthaline. 

 The author prepared from it nitronaphthaline and the compound 

 with picric acid. Naphthaline results from the condensation of 

 five molecules of acetylene under elimination of hydrogen, 



G 10 H 8 = 5(€ 2 H 2 )-H 2 ; 



and the liquid in which it was dissolved consisted probably of 

 pentacetylene, € 10 H 10 . Naphthaline is also formed to a slight 

 extent when pure acetylene is passed through a red-hot tube. 



Between 250° and 310° C. various hydrocarbons pass over, 

 which exhibit in a high degree the fluorescence of the hydrocar- 

 bons obtained by dry distillation of resins. No crystals could 

 be obtained from these liquids, and they were not further inves- 

 tigated; but the author believes that they contain six-, seven-, 

 and eight-times condensed acet}dene. 



At the boiling-point of mercury there distils a considerable 

 quantity of a hydrocarbon crystallizing in brilliant laminse which 

 on investigation were found to have all the properties of Retene, 

 G 18 H 18 , and, with picric acid, furnished the characteristic com- 

 pound discovered by Fritzsche. It must hence be regarded as 

 acetylene nine times condensed. 



