AMERICAN INSTITUTE. 397 



zine of food " at all times ready for use. A crop, when allowed 

 to remain over to the close of the second season, is estimated by 

 the French Institute at 2,000 bushels of sixty pounds each to the 

 acre. 



The cost of culture is less than that of the ordinary potato, 

 the expense of digging not exceeding one-fourth the usual cost, 

 as the root can be thrown out with the carrot or beet plough so 

 generally used in France on the immense plantations connected 

 with the beet sugar manufactories of that nation. It may be 

 successfully grown on any sandy, gravelly, or other permeable 

 soils that are neither very rich nor wet. In China it is cultivated 

 on terraced hill-sides and in localities where little else could be 

 produced. 



The culture of the different varieties is universal on account 

 of the certainty and abundance of the crops, arising from the 

 circumstance of this being the only alimentary root which, by 

 penetrating the earth vertically to a great depth, can make up by 

 its size and elongation for the great deficiency in the superficial 

 area of the land when contrasted with its population. 



Hitherto our surmises had fi.xed upon rice as being the only 

 alimentary plant capable of sustaining the vast population of 

 China; but when we recall to mind the fact that rice can only 

 be grown on wet soils, and requires irrigation, and that such soils 

 constitute but a small proportion of the land in populous coun- 

 tries, we are compelled to revert to the upland as the only means 

 by which an ample supply of food can be produced. 



Heretofore we have not been cognizant of any plant cultivated 

 on the upland that would produce a sufficient supply of food for 

 so redundant a population, and we are now amazed to find that 

 the present plant so far surpasses every other in alimentary 

 results, that a statistical investigation would prove that if China 

 were deprived of this one esculent and received in lieu of it 

 every other known vegetable, more than one half of her popula- 

 tion would perish from famine. 



Perhaps the most important fact is its not being subject to rot. 

 or decay, renderiug it possible to preserve it in a perfect state for 

 lengthy periods. This circumstance constitutes it the most impor- 

 tant esculent for prolonged sea voyages and for the prevention of 

 scurvy. And can we overestimate the importance of introducing 

 this new esculent to general culture throughout our country when 

 the potato rot has so materially diminished the average crops of 

 that root in most of the states, and when in portions of other 

 states its culture has been entirely abandoned. In my own be- 



