76 Chemical Society, 



nomena which form the subject of this communication were ob- 

 served. 



The salt was prepared by adding to a saturated boiling solution 

 of bitartrate of ammonia a saturated boiling solution of chlorate of 

 potassa, the liquor being strained from the precipitated cream of 

 tartar and cooled as rapidly as possible, it being observed that the 

 ammoniacal salt underwent a change if allowed to remain at a high 

 temperature for any length of time ; the solution was then care- 

 fully evaporated at a temperature below 100° Fahr., and again 

 strained from a small portion of cream of tartar which separated as 

 the liquor was concentrated. The chlorate of ammonia crystallizes 

 in small acicular crystals, or in plates similar to the chlorate of po- 

 tassa. The crystals are very soluble both in water and alcohol, and 

 have a sharp cooling taste. 



This salt was partially examined by Vauquelin, but he does not 

 appear to have observed the change it undergoes at the ordinary 

 temperature of the atmosphere, which most likely arose from his 

 using the salt immediately after it was prepared. 



In Murray's ' Elements of Chemistry,' vol. ii. p. 544, it is stated 

 that Vauquelin examined this salt : the author remarks, " it crystal- 

 lizes in fine needles, and appears to be volatile, as there is a consider- 

 able loss on evaporating its solution ; its taste is extremely sharp ; it 

 detonates when placed on a hot body with a red flame ; decomposed by 

 heat it gives out chlorine gas, with nitrogen and a little nitrous oxide, 

 hydrochlorate of ammonia with hydrochloric acid remaining." 



Brande states, in his ' Elements,' on the authority of Vauquelin 

 {Ann. de Chim. xcv. 97), that " this salt probably consists of one 

 proportional of each of its components, or 17 of ammonia -|- 76 of 

 chloric acid ; but its composition has not been experimentally de- 

 termined." I have analysed the salt, by decomposing it with 

 caustic potash, collecting the ammonia in water acidulated with 

 hydrochloric acid, and evaporating the solution carefully to dry- 

 ness ; the chloric acid was determined by igniting the salt, after the 

 action of potash, in a porcelain capsule ; then calculating the amount 

 by the weight of the resulting chloride of potassium, my results gave 

 one equivalent of ammonia, one of chloric acid, and one of water. 



After the salt had been prepared a few days, the colour was ob- 

 served to have changed from white to lemon-yellow, and gave out an 

 odour which powerfully affected the nose when held over the un- 

 corked bottle, irritating the eyes much more than chlorine, and cau- 

 sing a flow of tears ; this odour was dissimilar to that of any of the 

 oxides of chlorine. The salt was put away till an opportunity 

 should offer of examining the cause of this change. On going into the 

 laboratory some days after the alteration in the appearance of the 

 salt had been observed, the bottle, which contained about 4 ounces, 

 was found broken into innumerable particles, and the remains of its 

 contents strewed about the floor; on inquiry I was informed that 

 during my absence it had exploded with a loud report. Imagining 

 the explosion was produced by the bottle being closely stoppered, an 

 ounce of the salt was introduced into a very strong phial, and con- 



