CASSAVA— YAM— SWEET POTATO— ARROWROOT. 555 



Fortunately the deleterious principle is so volatile as to be entirely dissipated by 

 exposure to heat; for when the root has been cut into small pieces, and exposed 

 during some hours to the direct rays of the sun, cattle may be fed on it with perfect 

 safety. If the recently extracted juice be drunk by cattle or poultry, the animals 

 soon die in convulsions ; but if this same liquid is boiled with meat and seasoned, it 

 forms a wholesome and nutritious soup. The latropha janipha, or Sweet Cassava, 

 though very similar to the Manihot or bitter variety, and wholly innocuous, is far less 

 extensively cultivated. A palatable and wholesome bread is made of both kinds ; and 

 although its taste may be thought somewhat harsh by persons accustomed to soft fer- 

 mented bread made from wheaten flour, yet those who have been accustomed to its 

 use are so fond of it, that Creole families who have gone to live in Europe frequently 

 have it sent to them from the West Indies. The kind of starch so well known under 

 the name of tapioca is prepared from the farina of cassava roots. A large quantity is 

 exported from Brazil to Europe, and may well be considered as a more useful produc- 

 tion than all the diamonds of Minas Greraes. 



The Yam roots, which are so frequently mentioned in narratives of travel through 

 the tropical regions, are the produce of two climbing plants — the Dioscorea sativa and 

 Alata — with tender stems of from eighteen to twenty feet in length, and smooth, sharp- 

 pointed leaves on long foot-stalks, from the base of which arise spikes of small flowers. 

 The roots of the Dioscorea sativa are flat and palmated, about a foot in breadth, 

 white within and externally of a dark brown color, almost approaching to black ; those 

 of the D. alata are still larger, being frequently about three feet long, and weighing 

 about thirty pounds. Both kinds are cultivated like the common potato, which they 

 resemble in taste, though of a closer texture. When dug out of the earth, the roots 

 are placed in the sun to dry, and are then put into sand or casks, where, if guarded 

 from moisture, they may be preserved for a long time without being in any way 

 injured in their quality. The Dioscoroae are natives of South Asia, and are supposed 

 to have been thence transplanted to the West Indies, as they have never been found 

 growing wild in any part of America; while in the island of Ceylon, and on the coast 

 of Malabar, they flourish in the woods with spontaneous and luxuriant growth. They 

 are now very extensively cultivated in Africa, Asia, and America, as their large and 

 nutritious roots amply reward the labor of the husbandman. 



The Spanish or Sweet Potato, (Convolvulus batatas,) commonly cultivated in the 

 tropical climates both of the Eastern and the Western hemispheres, is an herbaceous 

 perennial, which sends out many trailing stalks, extending six or eight feet every way, 

 and putting forth at each joint, roots which in a genial climate grow to be very large 

 tubers, so that from a single plant forty or fifty large roots are produced. The leaves 

 are angular, and stand on long petioles, the flowers are purple. The batata is propa- 

 gated by laying down the young shoots in the spring ; indeed in its native climate it 

 multiplies almost spontaneously, for if the branches of roots that have been pulled up 

 are suffered to remain on the ground, and a shower of rain falls soon after, their vege- 

 tation will recommence. From its abundant growth, it is surprising that in Brazil the 

 mandioc should be cultivated in preference as food for the negro, the batata being 

 raised more as a luxury for the planter's table. 



Arrowroot is chiefly obtained from two different plants — the Marantha arundina- 

 coa and the Tacca pinnatijida. The former, a native of Soutn America, is an herba- 



