6 An Account of some Experiments on the 



cnverer of ihis coni|-oiincl, found it produced by the action 

 of nuiriat of lui on inuriat of' copper; he naiiifd it white 

 nuiriat ot copper, ami ascertained ihat a similar substance 

 resuhi from the decomposition of tlie common deliques- 

 cent niuriat by heat. 



Cuprinc, bv whatever means prepared, possesses the 

 same properties. It is fusible at a heit just below that of 

 redness, and in a close vessel, or a vessel with a very small 

 orifice, it is not decomposed or sublimed by a strong red 

 heat ; but if air, on the contrary, is freely admitted, it is 

 dissipated in dense white funics. It is insolulile in water. 

 It effervesces in nitric acid. It silently dissolves in 

 iDuriatic acid, from which it may be separated by the addi- 

 tion of water, which precipitates it unaltered; and it is de- 

 composed by a solution of potash ; or by heating it with 

 the fu>ed hydraied alkali ; when it affords the orange oxide 

 of copper. Its colour, transparency, and texture appear 

 alone to vary. It is oeneral'y opake, of a dark-brown co- 

 lour, and of a confused hackly texture; but I have ob- 

 tained it by cooling it slowly after it has been strongly 

 healed, of a light yello.v colour, semi-transparent, and cry- 

 stal'ized, apparently in small plates. 



Cupranea is only veiy slowly formed by heating cuprane 

 in chlorine gas. The best mode that I have found, of 

 procuring it, is by slowly evaporalinti to dryness, at a tem- 

 perature not much above 400" of Fahrenheit, the delique- 

 scent muriat of copper. Thus made, it has the same ap- 

 pearance, and the same properties, as when directly Ibrmed. 

 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 al'eration, clianges from yellow first to white, 

 and lastly to green. It is decomposed by heat; and even 

 in chlorine gas when the experiment is made on a pretty 

 large quantity, part of the chlorine is expelled, and assumes 

 the ffaseous state, and cuprane remams. 



1 have employed the same methods for ascertaining the 

 proportions of the constituent parts of both these com- 

 binations, I have separated the copper by iron, and the 

 chlorine bv means of niirat of silver, 



A solution of 80 grains of cuprane in nitro-muriatic 

 acid, precipitated by iron, afforded 31*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, aff"orded 117'5 grains 

 of horu silver dried, till it ceased to suffer any loss of^ 



weight 



