ROOT CROPS. 213 



already at the bottom of the hill. Had they lived on meat and 

 grain, they might have substituted a coarser fare ; but there is 

 no going behind the coarsest. Considering the peculiar social 

 state of Ireland, and especially the distribution and tenure of 

 land, the introduction of potatoes can scarcely be regarded as 

 a blessing. True, doctors disagree. Humboldt says that, 

 " from time immemorial, no plant has had so decided an influ- 

 ence on the prosperity of mankind as the potato." * But Dr. 

 Smee observes that " the potato is a plant of indolence, and 

 politically injurious to the community, when extensively em- 

 ployed. In Ireland it has begotten millions of paupers. "f 



Still every one knows that, in ordinary circumstances, pota- 

 toes are a profitable crop, and that they contain all the mate- 

 rials requisite for nutrition. Let two acres of land of the same 

 quality be cultivated, one with potatoes, the other with wheat. 

 Suppose the potatoes to yield two hundred bushels, weighing 

 ten thousand pounds ; of this weight, one-quarter is solid mat- 

 ter. We may admit the wheat to yield twenty-live bushels, 

 weighing fifteen hundred pounds ; of this, twelve hundred pounds 

 will be solid matter. How far these two portions of solid 

 matter will go towards supporting animal life is not so easily 

 settled. The potato has nearly as much of nutritious starch as 

 wheat. It has carbon, nitrogen, phosphorus, and lime, for the 

 development and support of the lungs, muscles, blood and 

 bones. In gluten it is deficient, and cannot, therefore, undergo 

 pannary fermentation and form a light loaf. In this respect wheat 

 flour stands before all other articles of vegetable food ; yet wheat 

 alone does not appear to be capable of supporting prolonged 

 human existence in the best health. Perhaps we should be 

 safe in asserting that, if one man was kept on bread made of 

 pure, fine wheat flour, and another on good boiled potatoes and 

 salt, the latter would live longer, and enjoy better health. The 

 bread is favorable to the increase of strength, and probably, 

 for a short time, the bread-eater could do the most work, while 

 the other would have better health, and last longer. Indeed 

 the best wheat bread is improved by the addition of potatoes, 



* New Spain, vol. ii. p. 449. t Smee, on the Potato Plant, p. 160. 



