6 WRITINGS OF JAMES SMITHSON. 



made perfectly pure by distillation. It did not seem by this 

 treatment to suffer any change, and after having been freed 

 from all adhering vitriolic acid by boiling in water, it had 

 not undergone any alteration either in its weight or proper- 

 ties. The vitriolic acid afforded no precipitate on being- 

 saturated with soda. 



(B) Two grains of Tabasheer reduced to fine powder were 

 made into a paste with some of this same vitriolic acid, and 

 this mixture was heated till nearly dry ; it was then digested 

 in distilled water. This water, being filtered, tasted slightly 

 acid, did not produce the least turbidness with solution of 

 soda, and some of it, evaporated, left only a faint black 

 stain on the glass, produced doubtless by the action of the 

 vitriolic acid on a little vegetable matter, which it had re- 

 ceived either from the Tabasheer, or from the paper. The 

 undissolved matter collected, washed, and dried, weighed 

 1.9 gr. 



VIII. 2 gr. of Tabasheer, reduced to fine powder, were 

 long digested in a considerable quantity of liquid acid of 

 sugar. The taste of the liquor was not altered ; and being 

 saturated with a solution of crystals of soda in distilled 

 water, it did not afford any precipitate. The Tabasheer hav- 

 ing been freed from all adhering acid, by very careful ablu- 

 tion with distilled water, and let dry in the air, was totally 

 unchanged in its appearance, and weighed 1.98 gr. This 

 Tabasheer being gradually heated till red hot, did not 

 become in the least black, or lose much of its weight, a 

 proof that no acid of sugar had fixed in it. 



With liquid alkalies. 



IX. (A) Some liquid caustic vegetable alkali being- 

 heated in a phial, Tabasheer was added to it, which dis- 

 solved very readily, and in considerable quantity. When 

 the alkali would not take up any more, it was set by to cool, 

 but was not found next morning to have crystallized, or un- 

 dergone any change, though it had become very concen- 



