1878.] 



Prof. M. Simpson. Chemical Notes. 



119 



no means a productive progress. I made an ineffectual effort to im- 

 prove it by surrounding the vessel containing the bromine with ice. 

 This, however, only made matters worse, as it caused the formation of 

 solid hydrate of chlorine and of bromine, which prevented the comple- 

 tion of the process. After several unsuccessful experiments I at last 

 hit upon the following process, which answers remarkably well : — 500 

 grains of bromine are dissolved in 4 fluid ounces of a mixture of equal 

 volumes of strong hypochloric acid and water. This solution is intro- 

 duced into a flask with a long neck, and surrounded with ice. Washed 

 chlorine is then passed into it with repeated agitation, till it ceases to 

 be absorbed. In this way not a trace of bromine is lost, nor are any 

 solid hydrates formed during the passage of the gas. On conducting 

 defiant gas into this solution, which should be surrounded with cold 

 water and repeatedly agitated, I obtained a large quantity of an oily 

 liquid, which I separated from the acid solution, washed with dilute 

 potash, and distilled. Almost the entire quantity passed over between 

 106° and 110°, most between 108° and 110°. 



The following analysis proves that this was the body in question in a 

 state of purity : — 



C 2 H 4 ClBr. 



Theory. Experiment. 



Carbon 1672 16-57 



Hydrogen .. .. 278 3*01 



This process yields nearly 80 per cent, of the theoretical quantity. 



Chloro-bromide of propylene (C 3 H 6 ClBr). 



This compound is prepared in exactly the same manner as the ethylene 

 compound. The propylene gas was derived from iodide of allyl. The 

 process is very productive. I obtained a large quantity of an oily 

 liquid, boiling between 118° and 120°, which proved on analysis to be 

 pure chloro-bromide of propylene. 



Chlor-dibrom Allyl (C 3 H 5 Br 2 Cl). 



This compound may be readily prepared by the action of the solution 

 of chloride of bromine upon bromide of allyl. It is only necessary to 

 leave these bodies in contact for two or three days at the temperature 

 of the air, and to agitate them repeatedly. The product distils between 

 197° and 199°. It gave on analysis numbers agreeing perfectly with 

 the above formula. 



Brom-dichlor Allyl (C 3 H 5 Cl 2 Br). 

 This body may also be formed by the action of chloride of bromine 

 upon bromide of allyl. To secure the production of this, and not the 

 other allyl compound, it is necessary whilst agitating the reacting 

 >odies, to maintain them at a temperature somewhat below 100° Cent. 



