CHEMICAL PRINCIPLES. 
549 
.grammes of mercury; and in the second, 6,557 grains of Oxides of gold, 
1 fgold by g,35 grains of mercury. 
Now Dr. Seft'crom has examined in my laboratory, and 
I 'while I was present, the exact composition of the oxides of 
f mercury, and has found that 100 parts of mercury combine 
with 7, 9 to 7 >99 parts of oxigcn, to produce the red ox;de. 
IBut it is evident that in the foregoing experiments, mercury ( 
'should form the red oxide, because the quantity of gold dis- 
isolved was in such excess, as necessarily to decompo>e the 
I insoluble muriate of the oxidule, if this were formed. In adopting 
ttherefore, the first of these two conclusions of M. Seft'irom as 
' tthe most correct, it follows that in the foregoing experimentj, 
1100 parts of gold gave to the mercury, in the latter 12,003, 
I jand in the former 12,0/7 parts of oxigen ; .igreeing so nearly 
I ttogether, that I consider these e.vpeiiiuents as sufticiently 
I (accurate- 
It therefore appears that the oxide of gold is composed of 
This analysis is confirmed by the experiments of M- Ober- 
1 Jkampf, on the sulphuret of gold obtained by precipitating the 
imuriate of gold with sulplunic gas a'ul hydrogen. He found 
ithat 100 parts of gold wer»' combhicd with 24,39 part* of 
' I sulphur, which coincides almost er. .ctl with the calculation, 
laccording to the chemical proportions- 
Whilst making these experuvet.ts, I obsened that the oxide 
I t of gold has the property of combining with a greater quantity 
of the muriatic acid, than is required to neutralize it. In which 
(case the muriate, with excess of acid, crystallizes in large prismatic 
crystals of an orange colour. The crystals are easily soluble ia 
'water, and the solution has a bright yellow' colour, Exposed to 
■ Iheat, they immediately dissolve in their water of crystallization; 
land if the heat be continued, the maria* c acid is separated, 
land the crystals are dried into a mass o a deep ruby colour, 
'which being dissolved in water, gives to it a red colour rcsem- 
Ibling that of a solution of the red oxide of iron. As it struck 
Gold 
S9.225 
10,7/5 
Oxigen 
me 
