240 CONSERVATIVE ORGANS. [LECT. V. 



tint, is yielded by the slender roots of Indian 

 Madder, Oldenlandia umbellata. The proper juice 

 of the Blood-root, Sanguinaria Canadensis, is 

 bright orange, and that of the Celandine, Cheli- 

 donium majm, is yellow; but I am not certain 

 that either of these have been employed as dye 

 stuffs. 



But it is in furnishing food that man has most 

 successfully exerted his ingenuity on these vege- 

 table organs. The roots of many plants, which 

 in a state of nature are small, have been enlarged 

 by cultivation, and rendered capable of yielding 

 a considerable supply of nutritious aliment ; for 

 example, the Carrot, the Turnip, the Beet, and 

 the Parsnip. Roots that are acrimonious and 

 poisonous when raw, are so altered by the art 

 of cookery, as to become mild, nutritious, and 

 wholesome food, owing to heat destroying the 

 acrimony upon which their injurious properties 

 depend : and, even by simple elutriation, one of 

 the most virulent of poisonous roots, that of 

 Jatropha manihot, is converted into Tapioca, a 

 mild fecula, well known for its nutritive qualities, 

 and universally employed as an article of diet in 

 convalescence and by persons of delicate habits. 

 By similar means many other roots, also, which 

 are now regarded as hurtful, might be rendered 

 inert ; and large additional supplies thus afforded 

 to the vegetable stores already selected for the 

 subsistence of the animal creation. 



