Rieth and Beilstein on the Synthesis of Propylene andAmylene. 217 



distillate is coutinually of a deeper colour, and in the retort a 

 mixture of sulphur and charcoal remains. 



Bisulphide of acetyle was treated with mercury in the antici- 

 pation of removing sulphur and forming free acetyle; a metallic 

 sulphide was formed, but an organic product free from sulphur 

 could not be obtained. 



The facility with which zincethyle is prepared by the method 

 described by Rieth and Beilstein*, has led these chemistsf to try 

 several reactions with it. In the expectation of forming an 

 allyle from an ethyle compound, they investigated the action of 

 chloride of carbon on zincethyle, which might take place in 

 the following manner : — 



GCl 4 + 2ZnG 2 H 5 = G 3 H 5 Cl + 2ZnCl + G 62 H 5 Cl. 

 This anticipation, however, was not realized; ethylene and pro- 

 pylene gases were obtained. The action is very energetic, and 

 only small quantities of the chloride must be added at once ; by 

 carefully regulating the temperature, a continuous disengage- 

 ment of gas is obtained. To free the gas from chloride of 

 ethyle, it is passed through sulphide of potassium and potash ; 

 it is then absorbed by bromine. When the action is complete, 

 the bromine is treated by caustic potash and then washed with 

 water, upon which a mixture in equivalent quantities of bromide 

 of ethylene and bromide of propylene is obtained. In reference 

 to this, the authors were enabled to confirm an observation which 

 had been already made by Bauer, namely, that it is impossible 

 to separate the two by fractional distillation. The boiling-point 

 rose at once to 135°, and between this temperature and 139° 

 the whole liquid passed over. The analysis of the product gave 

 numbers which are exactly intermediate between those required 

 by bromide of ethylene and bromide of propylene. The reac- 

 tion may be expressed as follows : — 



GCl 4 + 3Zn€ 2 H 5 = € 3 H 6 ' + £ 2 H 4 + 3ZnCl + G 2 H 5 C1. 



Chloride Zincethyle. Propylene. Ethylene, 

 of carbon. 



The action of chloroform on zincethyle was tried, in the expec- 

 tation that it might take place as follows, and produce propy- 

 lene gas : — 



GHCl 3 + 2ZnG 2 H 5 =G 3 H 6 + 2ZnCl + G 2 H 5 CL 

 Some propylene was indeed formed, but mixed with ethylene, 

 from which it could not be freed. But the principal product of 

 the reaction consisted of amylene, the formation of which may 

 be thus expressed : — 



GHCl 3 + 3ZnG 2 H 5 =G 5 H 10 + 3ZnCl + G 2 H 6 . 

 * Phil. Mag. vol. xxiv. p. 306. f Liebig's Annalen, November 1862. 



