76 FLINTY SECRETION. 



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 with extraordinary virtues. Some of 

 it, brought to England, underwent a che- 

 mical examination, and proved, as nearly as 

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

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

 Trans, for 1 790 and 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 

 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, Equisetum hy- 

 emale, Engl. Bot. t. 915. In the latter it is 

 very copious, and so disposed as to make a 

 natural file, 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 



