( 112 ) 



In the first place the action of bromine on the hydrocarbon was 

 studied. 



If to the hydrocarbon previously diluted with chloroform we add 

 drop l)y drop, while agitating vigorously with a Witt stirrer, a 

 solution of bromine in the same solvent, the temperature being — 10°, 

 the bromine is absorbed instantly and as soon as one molecule has 

 been taken up the liquid turns yellow when more is added. If at 

 that point the addition of bromine is stopped and the chloroform 

 distilled off in vacuo, a crystalline product is left saturated with an 

 oily snbstance. By subjecting it to pressure and by recrystallisation 

 from petroleum ether of low boiling point, fine colourless crystals 

 are obtained which melt sharply at 85°. 5 — 86° ^). 



A bromine determination according to Liebig gave 66.847o, CgHgBr, 

 requiring 66. 65°/o. 



A second bromine additive product, namely, a tetrabromide was 

 obtained by the action of bromine in chloroform solution at 0" in 

 sunlight; towards the end, the bromine is but slowly absorbed. The 

 chloroform is removed by distillation in vacuo and the product 

 formed is recrystallised from methyl alcohol. The melting point lies 

 at 114° — 115° and does not alter by recrystallisation. Analysis showed 

 that four atoms of bromine had been absorbed. 



Found: Br: 80.20. Calculated for C^H^Br, 79.99. 



A third bromine additive product was found for the first time in 

 the bromine which had been used in the preparation of the hydro- 

 carbon to retain any hexatriene carried over by the escaping gases. 

 Afterwards it was prepared by adding 3 mols of bromine to the 

 hydrocarbon diluted with 1 vol. of chloroform at 0° and then heating 

 the mixture at 60° for 8 hours. The reaction is then not quite com- 

 pleted and a mixture is obtained of tetra- and hexabromide from 

 which the latter can be obtained, by means of ethyl acetate, as a 

 substance melting at 163°. 5 — 164°. 



Found: Br. 85.76. Calculated for C^H^Br, 85.71. 



On closer investigation, the dibromide appeared to be identical 

 with a bromide obtained by Griner ') from s. divinyl glycol with 

 phosphorus tribromide; of which he gives the melting point as 

 84°. 5 — 85°. A product prepared according to Griner melted at 

 85^^.5 — 86° and caused no lowering of the melting-point when added 

 to the dibromide of the hydrocarbon. 



Griner obtained, by addition of bromine to the dibromide prepared 

 from his glycol, a tetrabromide melting at 112° together with a 



1) Not at 89° as stated erroneously in the previous communication. 



