172 Mr. j. Davy’s Account of some Experiments on the 
and the same properties, as when directly formed. It is of a 
yellow colour, and pulverulent. Exposed to the atmosphere, 
it is converted, by the action and absorption of water, into the 
deliquescent muriat, and its colour, during this alteration, 
changes from yellow first to white, and lastly to green. It is 
decomposed by heat ; and even in chlorine gas when the ex- 
periment is made on a pretty large quantity, part of the chlo- 
rine is expelled, and assumes the gaseous state, and cuprane 
remains. 
I have employed the same methods for ascertaining the 
proportions of the constituent parts of both these combinations. 
I have separated the copper by iron, and the chlorine by means 
of nitrat of silver. 
A solution of 80 grains of cuprane in nitro-muriatic acid, 
precipitated by iron, afforded 51.2 grains of copper, well 
washed, and perfectly dried. 
A solution of the same quantity of cuprane in nitric acid, 
precipitated by nitrat of silver, afforded 117.5 grains of horn 
silver dried, till it ceased to suffer any loss of weight by expo- 
sure to a temperature above 5C0 Fahrenheit. 
Since horn silver contains 24.5 per cent, of chlorine,* 80 
grains of cuprane appear to contain 51.2 grains of copper and 
28.8 of chlorine. And 100 appear to consist of 
36 chlorine 
64 copper 
100 
* This I have ascertained by synthesis ; 12 grains of pure silver dissolved in nitric 
acid, and precipitated with muriat of ammonia, yielded 15.9 grains of fused horn 
silver. 1 do not give the particulars of the experiment, which was very carefully made; 
because the result very nearly agrees with that of Klaproth, and of other chemists. 
