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GOLD. 
GOLD precipitated from aqua regia, and 
wafhed with hot water or boiled in a folution of 
alcaline fait, becomes red on being expofed to a 
flight heat. Lewis, Hiftory of gold, p. io8. 
2. The fame colour is produced when this precipi- 
tate of gold is ground with oil of vitriol, or fpirit 
of fulphur; or if it be mixed with fulphur, and 
the fulphur burnt away. Junker, tab. xxxiii. 
P* ^ 59 - 
3. The fmoaking fpirit of Libavius, mixed with 
gold and afterwards drawn off from it by diftil- 
lation, changes it’s colour to a blood red . — 
Sol fine vefte, exp. 19. Junker, tab. xxxiii. 
p. 861. 
4. Gold is reduced into a red powder, by amalga- 
mation with mercury, and expoling it for a 
conliderable time to a flow heat. — Boyle’s 
Abridg. vol. ii. p. 77. Junker, tab. xxxix. 
p. 987. 
3. if fix parts of antimony are fufed with one of 
gold, and the antimony driven off by the blaft, 
a red powder of gold is left behind. — Caffius de 
Auro, cap. 10. 
6. if gold leaf be cemented and ground with decre- 
pitated fait, hartfliorn, pumice, or chalk, and 
expofed to a proper heat, the metal becomes red, 
and may be precipitated from a folution of 
thofe fubftances in a red powder. — Junker, tab. 
XXXIII. p. 854. Lewis’s Hiftory of gold, p- 74 . 
Sol fine vefte, cap. 6. 
7 . A red 
