AMERICAN INSTITUTE. 381 



apparently firm mass, containing a small proportionate quantity 

 of nourishing matter. One pound of it may be made to form, 

 with water, a starchy mass weighing six pounds. It differs from 

 all other kinds of grain by containing so large a portion of starch 

 as we have named, and gluten insufficient for the sustenance of 

 the body, when no other food is used, unless eaten in inordinate 

 quantities, it possesses a few nitrogenous constituents, and a small 

 percentage of casein, or some analogous substance. 



Whereas, the potato, in addition to much water, consists of gum, 

 woody fibre, albumen and starch, in variable proportions, accord- 

 ing to variety, and the dry solid matter depends upon the state of 

 ripeness to which it has attained ; those perfectly ripe have 33 

 per cent of dry matter, and the imripe 23 per cent; starch varies 

 with variety from 10 to 28 per cent, and those keep the best, and 

 are less liable to rot, that contain the most starch; and at the 

 same time in keeping until spring, they lose a considerable quan- 

 tity of it, say from three to six per cent of their weight, which 

 diminution is caused by the conversion of the starch into gum and 

 sugar. 



When potatoes are frozen, and thawed sufficiently to render 

 them unfit for food, they are still capable of making cood starch, 

 as it undergoes no diminution. They also lose gluten by being 

 kept long after they are dug ; new potatoes contain usually 

 about three per cent, and old ones one and a half per cent; this 

 diminution of the proportion of gluten and starch, accounts for 

 the small value in stock feeding, agriculturists have experienced 

 old potatoes to possess. 



Potatoes thrive far better upon a light loamy soil, neither too 

 moist or too diy, than upon any other, and newly broken up pas- 

 ture land without manure, alwajs yields the best flavored. When 

 the soil is thoroughly drained, and subsoil plowed, they delight 

 in much rain, and no farmer on contiguous land, treated in a 

 different manner, by the aid of manure and skill, can raiee crops 

 of equal weight and quality. Warm climates, dry soils, and dry 

 seasons, largely increase the percentage of starch, which is some- 

 times defective in rainy districts. 



