[■15 3 
4. Kunkel prepared a powder for the fame purpofe, 
by precipitating the gold from the folution by 
an alkaline liquor 
5. Gold precipitated by tin from aqua regia, and 
melted with glafs in a proper proportion, tinges 
it with a beautiful ruby colour : this method 
was difcovered by Caflius [^], and farther im- 
proved by Kunkel [y']. 
6. The fame colour is produced by fufing gold 
with a large proportion of tin, and two thirds 
of lead, or by mixing it with regulus of anti- 
mony, or tin by calcination, and adding to glafs 
the powders of gold obtained from thefe pro- 
ceffes f^]. 
7. Gold amalgamated with mercury, and digefted 
with it for a conliderable time, may be reduced 
to a fubtile powder by expelling the mercury : 
this powder, melted into the glafs^ tinges it of a 
beautiful red [/6]. 
earthen pans, to calcine in the furnace, till it becomes a red 
powder ; which will be in many days ; then this powder, added 
in fuflicient quantity, and by little and little, to fine cryfal glafs^ 
which has been often call into water, will make the tranfparent 
red of a ruhy^ as by experience is found. 
[r/J Lewis’s Hiftory of Gold, p. 176. 
[^] Caflius de Auro, p. 105. 
[/] Junker, Confp. Chem. tab. xxxni. de Auro, p. 861. 
[^] Shaw’s Notes on Boerhaave’s Chem. vol. i. p, 78. 
[/’J Shaw’s Abridgement of Boyle, vol. i. p. 459. 
An induftrious perfon, having united Gold with a parti- 
cular quickfilver, kept them in digeftion for fome months ; when 
the fire having been immoderately increafed, the fealed glafs 
burft with a frightful noife; though the upper parts were blown 
ofF and fhattered to pieces, yet the lower efcaped tolerably whole; 
and I took notice, with delight, that it was tinged throughout 
of a fne and glorious redy hardly to be matched by that of Rubies, 
. 8. Gold 
