CHAPTER V. 



Various Uses to which Potatoes are applied. 



THE most important application of potatoes is as human 

 food ; on this it is unnecessary to enlarge. 



Einhoff found mealy potatoes to contain twenty-four per 

 cent, of their weight of nutritive matter, and rye seventy 

 parts ; consequently sixty-four and a half measures of pota- 

 toes afford the same nourishment as twenty-four measures of 

 rye. A thousand parts of potatoes yielded to Sir Humphrey 

 Davy two hundred to three hundred parts of nutritive matter, 

 of which one hundred and fifty-five to two hundred were 

 mucilage or starch, fifteen to twenty sugar, and thirty to forty 

 gluten. Now, supposing an acre of potatoes to weigh nine 

 tons, and an acre of wheat to weigh one ton, which is about 

 the usual proportion, then, as one thousand parts of wheat 

 afford nine hundred and fifty nutriiive parts, and one thou- 

 sand of potatoes say two hundred and thirty, the quantity of 

 nutritive matter afforded by an acre of wheat and potatoes 

 will be nearly as nine to four ; so that an acre of potatoes 

 will supply more than double the quantity of human food 

 afforded by an acre of wheat. The potatoe is, perhaps, the 

 only root grown, which may be eaten every day in the year 

 without satiating the palate. They are therefore the only 

 substitute that can be used for bread, with any degree of suc- 

 cess. In the answer by Dr. Tissot to M. Linquet, the for- 



