WRITINGS OF JAMES SMITHSON. 11 



colour. This glass was broken into pieces, and boiled in 

 marine acid. No effervescence appeared ; but the glass was 

 dissolved into a jelly. This jelly, collected on a filter, well 

 washed and dried, weighed 7.7 gr. 



The acid liquor which came through, on saturation with 

 soda, afforded not the least precipitate ; but, after standing 

 a day or two, it changed into a thin jelly. This collected 

 on a filter was washed with distilled water, and then boiled 

 in marine acid, but did not dissolve. Being again edulco- 

 rated, and made red hot, it weighed 1.6 gr. The filtered 

 liquor (B) would in all probability have changed similarly to 

 a jelly, had it been kept. These precipitates were analo- 

 gous to those § IX. (I). 



(D) An equal weight of vegetable alkali and Tabasheer 

 were melted together in the platina crucible. The glass 

 produced was transparent ; but it had a fiery taste, and soon 

 attracted the moisture of the air, and dissolved into a thick 

 liquor. But two parts of vegetable alkali, with three of 

 Tabasheer, yielded a transparent glass, which was perma- 

 nent. 



Treated with other fluxes. \ 



§ Xin. (A) A fragment of Tabasheer put into glass of 

 borax, and urged at the blow-pipe, contracted very consid- 

 erably in size, the same as when heated per se ; after which 

 it continued turning about in the flux, dissolving with great 

 difficulty and very slowly. When the solution was effected, 

 the saline pearl remained perfectly clear and colourless. 



(B) With phosphoric ammoniac (made by saturating the 

 acid obtained by the slow combustion of phosphorus with 

 caustic volatile alkali) the Tabasheer very readily melted 

 on the charcoal at the blow-pipe, with effervescence, into a 

 white frothy bead. 



(C) Fused, by the same means, on a plate of platina, with 

 the vitriols of tartar and soda, it appeared entirely to resist 

 their action ; the little particles employed continuing to re- 

 volve in the fluid globules without sustaining any sensible 



