PRODUCTS OF POTATOES. 125 



to be the cause of the disease. It is caused also by using seed stock 

 exposed to the light or air during the winter; it should be covered to 

 protect its juices. The eyes of the tuber also vary in this particular, 

 as those nearest the end securing the tuber to the plant ripen first, 

 while those of the other, or larger end, are soft and waxy and best 

 suited for planting. High culture and stimulating manures induce this 

 disease, or it arises from properties left in the soil by previous crops. 

 It is less frequent in new lands and in cold upland places. 



The production of an acre of land with the same care and manuring 

 as with wheat, may produce 300 bushels of potatoes, or 24 bushels of 

 wheat. The food of the first, at 38 Ibs. the bushel, will be 1 1,400 Ibs. 

 weight, and that of the second at 60 Ibs. the bushel will be 1,400 

 Ibs. or of the first by weight. Wheat contains about 3 times as 

 much mucilage or starch and of gluten or albumen as the same 

 weight of potatoes, but it is deficient in saccharine matter, while the 

 potato contains from 3 to 4 per cent of it. It has been estimated that 

 2 Ibs. of wheat are equal to 7 pounds of potatoes, the mean weight 

 being as stated 1 to 8 ; if, therefore, 480 ibs. of wheat be required for 

 each individual, or its equivalent 1680 Ibs. of potatoes, an acre of 

 wheat will sustain 3 persons and an acre of potatoes will support 6|, 

 or more than twice the number. 



The average produce in Ireland is considered 82 barrels the acre, 

 or 22,960 Ibs. If 4 pounds of potatoes are equal to a pound of wheat, 

 the above amount divided by 4 will give the amount of nutriment as 

 5.740 Ibs. The relative proportion of solid nutriment yielded by 

 an acre of wheat and of potatoes is estimated by Mr. Young as 1 

 to 3. According to Sir H. Davy, wheat yields 950 parts of nutri- 

 tive matter in 1000, and potatoes 230 in 1000, the product of an acre 

 of potatoes being 9 tons and of wheat 1 ton ; the quantity of nutri- 

 tive matter will therefore be as 9 to 4 or more than double, so that 

 the population of a potato feeding country, other things being equal, 

 may be from 2 to 3 times more dense than if fed entirely on corn 

 plants. Still, the use of potatoes wholly, cannot be desirable, nor 

 is their accumulation and preservation in quantities without many 

 difficulties. It appears therefore important and desirable that the pro- 

 ducts of a country should not be wholly one or two kinds, but as va- 

 ried, if possible, as we find them at present in our own country. The 

 use of potatoes in the composition of bread appears to be greatly in- 

 creasing. It is said that 40,000 tons of potatoes are annually made 

 into flour, for the purpose of uniting it in the formation of bread, 

 within a circuit of 8 leagues around Paris. The estimated annual 

 product of potatoes and chestnuts in France is 130,000,000 bushels 

 and the estimated annual value of potatoes in the kingdom of G. B. is 

 about 12 millions sterling. 



The products of potatoes are various. Alcohol is extracted from 

 11* 



