Min ERA Logy. 145 
SECT. CXXXIXi 
b. Borax. 
This is ^ peculiar alcalirie fait, which is 
ruppofed to belong to the mineral kingdom^ 
and cannot be otherwife defcribed, than that 
it is either fome unknown alcali, united 
with an earthy which is diffoluble in water^ 
and vitrefcible i or an alcaline fait, which is 
fixed in the fire, and melts to a glafs,; which 
glafs is afterwards diiToluble in water. 
Many experiments have been made with 
it, in order to difcover its origin and conftitu- 
ent parts, and therefore it is arriply treated 
of in chemical books \ and its following qua- 
lities are to be obferved. 
1 . It fwells and froths in the fire, as long as 
any humidity remains in it, but melts af- 
terwards very eafily to a tranfparent glafs, 
which, as it has no attradtion to the phlo- 
gillon, keeps itfelf in the form of a pearl 
on the charcoalj when melted with the 
blowpipe; 
2. It changes the fyrlip of violets into green | 
%nd precipitates the folution of dlum, and 
that of metals^ made with acids. 
3. It unites with mineral acids to a neutral 
fait, which flioots into very fine and fubtile 
hair-like criftals, and is called fal fedativumi. 
In a certain compofition it is volatile ^ and 
mixed with litmus^ or fuccus heliotropn^ and 
the fyrup of violets, it difcovers marks 
both of an alcali and an acid. 
4. W hen it has been united with the vitriolic 
acid and a phlogiilon, no hepar fiilphuris is 
produced. 
I 
5. After 
