Borax defer ibed , and its Ufe. 107 
Lumps or Cryftals, of a yellowifh and 
fometimes of a dirty green Colour : but we 
really know little thereof with Certainty. 
The Venetians made great Profit heretofore 
by purifying it for Sale but that Trade 
at prefent is chiefly carried on by the Dutch ; 
though I am told the Secret is become 
known, and has lately been pra&ifed with 
good Succefs in England. It ferves the fame 
Purpofes of fufing and foldering Gold and 
other Metals, as the Chryfocolla of the An¬ 
cients did, for which Reafon it is frequent¬ 
ly called by the fame Name, though theirs 
was quite another kind of Subftance, the 
Knowledge whereof is probably loft to us* 
Its glaffy Quality renders it ufeful in dying, 
to give a Glofiinefs to Silks $ and Dr. Shaw 
proves (in the twentieth of his Chemical Lec¬ 
tures, Experiment 3d.) that by means of 
this Salt a Kind of Glafs may be made 
of an extraordinary Degree of Hardnefs ■% and 
imagines the Arts of Enamelling, and of 
imitating precious Stones, may be greatly 
improved thereby 
* Vid. Shaw's 'Translation of Boerhaave's Chemijlry , Vol. I. 
p. 110, in the Notes. 
f Rough Borax is called Tincal , or Tincar. Geojfroy fays, 
a fait, muddy, greenilh Water, found in fome Copper Mines, 
evaporated to a certain Degree, then kept for feveral Months 
in Pits, whofe Sides and Bottoms are plaiftered with the Mud 
of the fame Mines mixt with Animal Fat, the Pits being alfo 
covered with the fame Plaifter, produces the Lumps or Cry¬ 
ftals of unrefined Borax. 
When 
