[ 29 ] 
7* A red tindlure may be prepared from gold by 
feveral methods mentioned byLibavius, Alchem. 
lib. ii. p. 130. Junker, tab. xxxiii. p. 868. 
8. A folution gold in aqua regia prepared from 
fal ammoniac may be fublimed of a blood red 
colour. The fame is effedled by diffolving the 
calx, or crocus of goldy in other menftrua. 
Lewis’s Hiftory of gold, p. 100. Junker, tab. 
XXXIII. p. 857. 
9. A folution of gold in aqua regia, evaporated pro- 
perly, affords cryftals of a bright red colour.— 
Caflius de Auro, p. 109. Junker, tab. xxxiii. 
p. 862. 868. Lewis’s Hiftory of gold, p. 99. 
10. Aurum fulmmans moiftened with water, has 
been found to tinge gems deeply of a fine red. 
Phil. Tranf. N°. 179. 
1 1. A folution of gold tinges ivory, cotton, the 
fkin, and other fubifances red. 
Rubies being frequently found in gold minesy it is 
very probable that they receive their colour from 
that metal ; and from this circumftance, before the 
experiment had been made, Libavius rightly con-’ 
je(Sured that a folution of gold would communicate 
a ruby colour to glafis. Libavii Alch. p. 88. 
It does not appear that, excepting the colour 
natural to gold in its intire date, any other than’ 
red can be obtained from preparations of this metal : 
it is from this colour, which gold affumes when- 
ever its metallic brightnefs is deflroyed, that 
writers in chemiftry call it leo ruber \i\. 
[e] Libavius de natura inetallorum, lib. i. cap. 4. de auro. " 
In iuo manifefto cittinum eft, in occulto fummam continet rul?e- 
2 LEAD. 
