504- Prof. Kane on the Action of Ammonia 



into a full investigation of this theory mathematically : but 

 now my age forbids ; it remains therefore only for me earnest- 

 ly to recommend these labours, which I am sure will yield 

 abundant fruit, to the consideration of the real lovers of 

 science. 

 Bristol, Sept. 29th. 1837. Thomas Exley. 



LXXI. On the Action of Ammonia on the Protochloride and 

 Peroxide of Mercury. By Robert Kane, M.D., M.R.I.A., 

 Sfc. fyc* 



Of the Action of Ammonia on the Protochloride of Mercury, 



§ 1. — Action of Liquid Ammonia up o?i Calomel. 



HPHE decomposition resulting from the action of water of 

 ammonia upon the protochloride of mercury, does not ap- 

 pear to have attracted particular attention, as all writers who 

 speak at all upon the subject, mention ammonia, along with 

 potash and soda, as decomposing calomel into black oxide of 

 mercury. Hennell in particular, states expressly, that calomel 

 decomposed by excess of ammonia, yields a black powder 

 containing in 100 parts, 96 of mercury and four of oxygen. 

 I was therefore rather surprised when experiment showed 

 me that a reaction of a totally different nature takes place, 

 giving rise to a compound possessed of very remarkable pro- 

 perties. 



When water of ammonia is poured on calomel, whether 

 sublimed or precipitated, the mass immediately becomes black, 

 and the appearance is not altered by boiling the mixture for 

 along time. While yet wet the powder remains almost black, 

 but it becomes much lighter on drying, so that when quite 

 dry it is of a dark-gray. This powder is not altered by ex- 

 posure to air, or to a moderate heat ; a portion of it was ex- 

 posed in a platinum crucible on a sand-bath for several hours 

 to a temperature of 180° Fahrenheit, without being altered in 

 weight or colour. When moistened it becomes nearly as dark 

 as when first generated, but it again loses its black colour on 

 being dried ; boiled with water it does not appear altered in 

 its composition. When this powder is heated in a tube 

 sealed at one end, it first gives a trace of water, with much 

 azote and ammonia; then there sublimes calomel mixed with 

 metallic mercury, the decomposition being accompanied with 

 that sort of effervescence which appears in the heating of so 

 many of the substances under examination. 



* From the Trans. Roy. Irish Acad., vol. xvii. p. 441 ; being Sections If. 

 and III. of the author's "Researches on the Action of Ammonia upon the 

 Chlorides and Oxides of Mercury;" in continuation from p. 435 of our 

 last number. 



