258 Dr. Simpson on a New Base obtained by 



the mixture is exposed in sealed tubes to the temperature of a 

 water-bath for about ten or twelve hours. Decomposition com- 

 mences almost immediately, and a large quantity of a white salt is 

 ])recipitated, which I afterwards ascertained by analysis to be pure 

 bromide of ammonium. At the expiration of the above-mentioned 

 time the tubes were opened, and the bromide separated by filtra- 

 tion. On adding a large quantity of water to the filtrate it became 

 turbid, and deposited after some time a heavy oil, which is the 

 base in question, contaminated with some undecomposed terbro- 

 mide. This was well washed with water, dissolved in dilute 

 hydrochloric acid and filtered. The filtered liquor was then ex- 

 posed to the temperature of 100'' C. till all the water had been 

 driven off, and it ceased to evolve acid vapours. After the ex- 

 pulsion of the water the salt melted, but became solid again on 

 cooling. To purify the salt it was now dissolved in water, fil- 

 tered to remove a trace of oil, and evaporated to dryness again. 

 It was then washed with a;ther, in which it is but little soluble, 

 and finally dried over sulphuric acid in the vacuum of an air- 

 ])ump. The salt thus prepared proved on analysis to be a species 

 of hydi't)chlorate of ammonia, in which two equivalents of hy- 

 drogen are replaced by two equivalents of the monobasic radical 

 C^H^Br, thus:— 



HI rC«H4Br] 



^•l H ^HCl, N^ C^H^B 



UJ I H J 



Hydroelilorate of Hytlrochlorate of 



ammonia. c'ibromallylammonia. 



Its formation may be thus explained : — 



Q6 H5 Br3 + NH3 = C^ H'» Br^ + NH^, HBr, 

 and 



rCH^Br^ 

 2(C6 H'' Br^) + 3NH3= N ^ C« H^ Br V + 2(NH3, HBr). 



The base dissolved in the hydrochloric acid gives the salt. 

 The analysis of the salt gave the following numbers : — 



I. 0-3911 grm. of salt gave 0-3505 grm. carbonic acid and 

 0-1285 water. 



II. 0-4053 grm. of salt gave 0-3540 grm. carbonic acid and 

 0-1375 water. 



III. 0-G905 grm. of salt gave 27*5 cubic centims. of moist 

 nitrogen, barometer 760 millims., thermometer 12° C. 



IV. 0-8585 grm. of salt, burnt with soda-lime, gave 0'3016 

 grm. platinum. 



V. 0-4958 grm. of salt gave 0-2536 grm. chloride of silver. 



