194 On the Potato as National Diet, 



other instance in "which a root has hecome the staple and 

 almost the only food of a nation ; neither the yam nor 

 sweet potato are used to this extent. The tapioca plant, 

 which yields a very important article of food in the tropical 

 parts of America, and the arum, employed as a common 

 diet in the South Sea Islands, are by no means the sole 

 diet ; they have in America beef, besides flesh of the guanaco 

 and ostrich, several varieties of deer, bear's flesh, &c. ; and 

 in the Isles of the South Sea, they have the yam, the 

 banana, the arum, and bread-fruit, with the flesh of the pig 

 superadded. 



The single vegetable which sustains, without doubt, the 

 largest number of human beings is the rice plant; the 

 myriad labouring classes of India and China are thus sup- 

 pjorted : and although rice is much less subject to failure 

 than the potato, yet the main dependence for food being 

 upon a single article, causes the countries in which it prevails 

 to be exposed to the most fearful visitations of famine and 

 pestilence. As a proof of the wide range of excess and of 

 failure of crop to which the potato is subject, it may be 

 mentioned that, in years of scarcity, it has been known to 

 be ten times as dear as in seasons of plenty ; whereas the 

 range of wheat does not exceed two, or at most three, times 

 its average rate in modern cultivation. The failure of the 

 potato crop has been more frequent of late than in former 

 years. Witliin the last twenty years, the following may be 

 taken as years of partial or wide-spread failure : — 1831, 

 1835, 1836, 1837, and 1839. The potato disease, which had 

 appeared in North America in 1844, showed itself in Ireland 

 in 1845, increased in 1846, was of milder type in 1847, and 

 returned with greater virulence in 1848. The causes thereof 

 are several. Population has increased, and consumption has 

 been proportionally augmented ; it has been necessary, in 

 consequence, oftener to repeat the crop in the same ground. 



