76 FLIMTY SKCRIiTION. 



called Tabaxir or Tabasheer, which is suppo- 

 sed in the East Indies (probably because it is" 

 rare and difficult of acquisition, like the ima- 

 ginary stone in the head of a toad) to be en- 

 dowed vvith extraordinary virtues. Some of 

 it, brought to England, underwent a che- 

 mical examination, and proved, as nearly as 

 possible, pure fiint. See Dr. Russell's and 

 Mr. Macie's papers on the subject in the Fhil. 

 Trans, for V(^Oand 1791- It is even found 

 occasionally in- the Bamboo cultivated in our 

 hot-houses. But we need not search exotic 

 plants for flinty earth. I have already, in 

 speaking of the Cuticle, chapter 3d, alluded 

 to the discoveries of Mr. Davy, Professor of 



Chemistry at the Royal Institution, on this 



x/ ■J ' 



subject. That able chemist has detected pure 

 flint in the cuticle of various plants of the fa- 

 mily of Grasses, in the Cane (a kind of Palm) 

 and in the Rough Horsetail, Eqinsetum hy- 

 ernale, Engl. Bot. t, 9^5, . In the latter it is 

 very copious, and so disposed as to make a 

 natural tile, which renders this plant useful 

 in various manufactures, for even brass can- 

 not resist its action. Common Wheat straw, 

 when burnt, is found to contain a portion of 



