380 Mr . Macie’s Account of 
(C) 10 gr. of Tabafheer, reduced to powder, were mixed 
with an equal weight of foda, deprived of its water of cry- 
ftallization by heat. This mixture was put into a platina cru- 
cible, and expofed to a ftrong fire for if. It was then found 
converted into a tranfparent glafs of a flight yellow colour. 
This glafs was broken into pieces, and boiled in marine acid. 
No effervefcence appeared ; but the glafs was diffolved into a 
jelly. This jelly, collected on a filter, well wafhed, and dried, 
weighed j.j gr. 
The acid liquor which came through, on faturation with 
foda, afforded not the leaft precipitate ; but, after Handing a 
day or two, it changed into a thin jelly. This colle&ed on a 
filter was wafhed with diftilled water, and then boiled in ma- 
rine acid, but did not diflolve. Being again edulcorated, and 
made s red hot, it weighed 1.6 gr. The filtered liquor (B) 
would in all probability have changed fimilarly to a jelly, had 
it been kept* Thefe precipitates were analogous to thofe 
§ IX. CO- 
CD) An equal weight of vegetable alkali and Tabafheer 
were melted together in the platina crucible. The glafs pro- 
duced was tranfparent ; but it had a fiery tafte, and foon at- 
tracted the moifture of the air, and diflolved into a thick 
liquor. But two parts of vegetable alkali, with three of Ta- 
bafheer, yielded a tranfparent glafs, which was permanent. 
Treated with other fluxes . 
§ XIII. (A) A fragment of Tabafheer put into glafs of 
borax, and urged at the blow-pipe, contracted very confiderably 
in fize, the fame as when heated per fe ; after which it conti- 
nued turning about in the flux, diffolving with great difficulty 
and 
1 
