10 WRITINGS OF JAMES SMITHSON. 



This powder was insoluble in vitriolic acid, and seemed still 

 to be Tabasheer. 



Some of this clear liquor, mixed with marine acid, effer- 

 vesced; did not afford any precipitate; but, on standing 

 some days, the mixture became slightly gelatinous. 



(G) Some of the thick jelly remaining on the filter, being 

 boiled in water and in marine acid, appeared insoluble in 

 both, and seemed to agree entirely with the above powder 

 (F). 



With dry alkalies. 



§ XII. (A) Tabasheer melted on the charcoal at the blow- 

 pipe with soda, with considerable effervescence. When the 

 proportion of alkali was large, the Tabasheer quickly dis- 

 solved, and the whole spread on the coal, soaked into it, and 

 vanished ; but, by adding the alkali to the bit of Tabasheer 

 in exceedingly small quantities at a time, this substance was 

 converted into a pearl of clear colourless glass. 



(B) 5 gr. of Tabasheer, reduced to fine powder, were 

 melted in a platina crucible with 100 gr. of crystals of soda. 

 The mass obtained was white and opaque, and weighed 40.2 

 gr. Put into an ounce of distilled water, it wholly dissolved. 

 An excess of marine acid let full into this solution produced 

 an efiervesccnce, and changed it into a jelly. This mixture 

 was stirred about, and then thrown upon a filter. The jelly 

 left on the paper did not dissolve in marine acid by ebulli- 

 tion ; collected, washed with distilled Water, and dried, it 

 weighed 4.5 gr. and seemed to be the Tabasheer unaltered. 

 The liquor which had come through being saturated with 

 mineral alkali yielded only a very small quantity of a red 

 precipitate, which was the colouring matter of the pink 

 blotting paper through which it had been passed. 



(C) 10 gr. of Tabasheer, reduced to powder, were mixed 

 with an equal weight of soda, deprived of its water of crys- 

 tallization by heat. This mixture was put into a platina 

 crucible, and exposed to a strong fire for 15'. It was then 

 found converted into a transparent glass of a slight yellow 



