recourse to an artificial mode of culture. They trench the ground five feet 

 deep, and place the entire deposit of -manure at the bottom, leaving the other 

 portion of the soil sterile. When thus prepared, they select a peculiar variety 

 of the Yam, which has a propensity to penetrate deeply, and this root seeking 

 for the aliment below penetrates to the depth of 40 inches, forming immense 

 roots, and yielding thus a treble crop. By this mode of culture they obtain 

 from a space of land 12 feet by 3, a sufficiency of food to sustain a man a year. 

 It would seem that Nature desired to impart to this plant every estimable char- 

 acteristic required as a special provision for an abundant crop of the long 

 varieties of this Yam, and that these were in exact accordance with what the 

 circumstances demanded in the Chinese Empire, the regular vertical growth of 

 the root without any branching, it thus occupying no extra space in the earth, 

 but allowing for the entire occupancy by the greatest possible number of plants 

 in a given space. 



Another important fact is, that the roots of the long varieties penetrate so 

 deeply into the earth, that no drought can affect them, and they evidently draw 

 a larger portion of their nutrition from the depth of the earth than from the 

 atmostphere, as is plainly evinced by the comparatively diminutive develop- 

 ment of vines and foliage. These points, when duly considered, must be deemed 

 most important and interesting facts for the reflective mind. In the Chinese 

 Agricultural Books we find more pages devoted to the culture of this Esculent, 

 and to the descriptions of the many varieties than to any other Agricultural 

 object whatever. Why is this, and how is it to be accounted for, except by the 

 greater appreciation of its National importance? We find there that a plantation 

 of this root is termed, " A permanent Magazine of Food," and that the roots 

 are dug for use every day throughout the year, thus always furnishing a fresh 

 supply of what we should term, " New Potatoes." We further find that when 

 this plantation or magazine of food is once established, it does not require 

 renewal annually, but that the small sections of roots which are broken off and 

 the numerous tubers produced, continually replenish all exhaustion, in the same 

 manner as is done in. our Horse Kadish fields. In China where the area of land 

 is so disproportionate, the hill sides which would otherwise be useless, are 

 terraced and planted with this root, which seemingly will flourish anywhere. 

 The plantations cover every available location, and are denominated by them 

 " A Grand National Kesource." This Yam furnishes flour of a purer whiteness 

 than wheat, and which surpasses it in nutritious and farinaceous excellence, and 

 may be applied to all similiar purposes as food. It supplies all their bread, and 

 is used in pastry and every other way. It is furthermore declared to be highly 

 beneficial to invalids, and especially so in diseases of the chest, and to be the 

 great preventive of consumption, a disease which seems to be unknown in that 

 country. And indeed, its nitrogenous constituent would impart to it this 

 character, and more especially so when a total abstinence from meat as food 

 exists, which is of itself one of the greater promotives of Consumptive 

 affections. 



Why has this Esculent been hitherto Unknown ? 



To the many inquiries, why we have not obtained this important Esculent 

 before, I answer, that our only intercourse with China until of late years was 

 interdicted to Canton, a port within the Tropics, and from which we obtained 

 only tropical products, one of which was the Chinese Tropical Yam — Dioscorea 

 Sativa — long cultivated extensively in the West India Islands, and elsewhere in 

 the Tropics, but which is entirely unsuited to Northern latitudes. It was not 

 until Shanghae and other ports of Northern China were opened, more than a 

 thousand miles distant from Canton, that we became familiarized with the pro- 

 ductions of Northern China and Tartary, extending to the limits of the Tern- 



