2 WRITINGS OF JAMES SMITHSON. 



possessed a small degree of transparency, and had a bluish 

 cast. The latter, held before a lighted candle, appeared very 

 pellucid, and of a flame colour. 



The pieces were of various sizes ; the largest of them did 

 not exceed two or three-tenths of an inch cubic. Their 

 shape was quite irregular; some of them bore impressions 

 of the inner part of the bamboo against which they were 

 formed. 



(B) This Tabasheer could not be broken by pressure be- 

 tween the fingers ; but by the teeth it was easily reduced to 

 powder. On first chewing it felt gritty, but soon ground to 

 impalpable particles. 



(C) Applied to the tongue, it adhered to it by capillary 

 attraction. 



(D) It had a disagreeable earthy taste, something like 

 that of magnesia. 



(E) No light was produced either by cutting it with a 

 knife, or by rubbing two pieces of it together, in the dark ; 

 but a bit of this substance, being laid on a hot iron, soon 

 appeared surrounded with a feeble luminous aureole. By 

 being made red hot, it was deprived of this property of 

 shining when gently heated; but recovered it again, on 

 being kept for two months. 



(F) Examined with the microscope, it did not appear dif- 

 ferent from what it does to the naked eye. 



(G) A quantity of this Tabasheer which weighed 75.7 gr. 

 in air, weighed only 41.1 gr. in distilled water whose tem- 

 perature was 52.5 F. which makes its specific gravity to be 

 very nearly = 2.188. 



Mr. CAVENDISH, having tried this same parcel when be- 

 come again quite dry, found its specific gravity to be = 2.169. 



Treated with water. 



II. (A) This Tabasheer, put into water, emitted a num- 

 ber of bubbles of air; the white opaque bits became trans- 

 parent in a small degree only, but the bluish ones nearly as 

 much so as glass. In this state the different colour pro- 



