22 
Copper . 
This ore was analyzed by Klaproth in the following 
simple manner, its general contents having been ascertain- 
ed by the above-mentioned experiments. One hundred 
grains of the ore were dissolved in nitric acid without 
heat, during which about 11-2 of iron ochre was deposit- 
ed. It was then diluted and nitrat of silver added to as- 
certain the quantity of luna cornea. Of this last, 64 1-2 
grains were obtained, of which 10 grains were muriatic 
acid, according to separate experiments by which it ap- 
pears that 100 grains of silver form 133 of luna cornea, 
and of the 33 grains additional weight, 12 1-2 are oxy- 
gen, and 20 1-2 muriatic acid. The copper was then 
precipitated as usual by iron, and weighed 57 1-2 grains 
in the metallic state, equal to 73 of the brown oxyd» 
Klaproth does not consider the iron however as essential 
to the ore, and therefore excludes it from the estimate. 
Phosphat of Copper * 
This rare metal was analyzed by Klaproth in the follow- 
ing way. It was first dissolved in nitric acid, which 
made a clear blue solution, leaving untouched 16 parts 
out of 100, which were quartz. The solution was then 
just saturated with potash to engage any excess of nitric 
acid, and acetited lead was then added, which gave a co- 
pious white precipitate, and a small excess of the acetite 
was used to ensure the complete precipitation. This 
white insoluble salt from appearance might be either sub 
phat, or arseniat, or muriat, or phosphat of lead, but it 
was proved to be the latter by the two following tests ; 
1st. when fused by the blowpipe, in the moment of cool- 
ing it assumed a garnet-like form with shining surfaces, 
which sudden crystallization is peculiar to phosphat of 
lead ; and 2diy, when digested with dilute sulphuric acid, 
sulphat of lead was formed, and naked phosphoric acid 
remained in the liquor, which being neutralized, partly 
by soda and partly by ammonia, gave the well-known 
microcosmic salt. The native phosphoric acid was there- 
