AN ACCOUNT OF SOME CHEMICAL EXPERI- 

 MENTS ON TABASHEER. 



From the Philosophical Transactions of the Koyal Society of London. 

 Vol. LXXXI, for the year 1791, Part 2, p. 368. Read July 7, 1791 . 



The Tabasheer employed in these experiments was that 

 which Dr. RUSSELL laid before the Society, as specimens of 

 this substance, the evening his Paper upon the subject was 

 read.* 



There were seven parcels. 



No. 1 consisted of Tabasheer extracted from the bamboo 

 by Dr. RUSSELL himself. 



No. 2 had been partly taken from the reed in Dr. Rus- 

 SEL'S presence, and partly brought to him at different times 

 by a person who worked in bamboos. 



No. 3 was the Tabasheer from Hydrabad ; the finest kind 

 of this substance to be bought. 



Nos. 4, 5, and 6 all came from Masulapatam, where they 

 are sold at a very low price. These three kinds have been 

 thought to be artificial compositions in imitation of the true 

 Tabasheer, and to be made of calcined bones. 



No. 7 had no account affixed to it. 



The Tabasheer from Hydrabad being in the greatest quan- 

 tity, and appearing the most homogeneous and pure, the 

 experiments were begun, and principally made, with it. 



Hydrabad Tabasheer. (No. 3.) 



I. (A) This, in its general appearance, very much re- 

 sembled fragments of that variety of calcedony which is 

 known to mineralogists by the name of Cacholong. Some 

 pieces were quite opaque, and absolutely white ; but others 



* See Phil. Trans. Yol. LXXX, p. 283. 



