io 8 Borax deferibed, and its Ufe, 
When refined and pure it is brought in 
large cryftaline Shoots clean and white, 
about the Clearnefs and Hardnefs of Alum, 
wherewith it is fometimes adulterated: to 
the Tafte it is almoft infipid, but fomewhat 
fmooth and oily, and the more fo the lefs it 
has been purified, for in its foul State ftis 
confiderably fat and greafy. 
A regular Cryftal of fuch purified Borax, 
as taken by the Microfcope, is {hewn on the 
Side of the Drop at A. 
Some Years ago my worthy Friend Mr. 
Peter Colinfon , F. R. S. favoured me with a 
Subfiance faid to be brought from Perfia , 
and called Native Borax : > tis in fmall, irre- 
gular, flattifh Pieces, of a gre'yifh white Co¬ 
lour, wherein, if nicely examined, abun- 
dance of fhining Particles may be difeerned : 
it is light and porous, of a very brittle 
Confidence, fomewhat urinous, and more 
pungent in Tafte than the Kind before 
deferibed. A Solution of this did not fhoot 
at all into Cryftals, but in many Exami¬ 
nations filled the whole Drop with figur’d 
Bodies like that at B ; which, from being 
barely vifible, enlarged pretty faft, to a 
Size (when viewed by the fourth Magni¬ 
fier) as big in Appearance as the Figure 
here exhibited. 
Thefe quickly fall to Pieces, and become 
dfftblved by the Air. 
C H A P* 
i 
