THE TECHNOLOGIST. 



THE POTATO AND ITS COMMERCIAL PRODUCTS. 



BY THE EDITOB. 

 (Concluded from vol. i., p. 340.) 



Perhaps there is no vegetable that has suffered more romantic vicissitudes 

 in its fame and propagation than the potato. It has been successfully 

 opposed, commended, and eulogised by priests and kings. This once 

 insignificant production has succeeded in diffusing itself through almost 

 every climate, and ministering to the tastes and appetites of the civilised 

 world 



Scientific research has extended the numerous resources which this 

 plant is so wonderfully calculated to furnish. Thus, besides the uses already 

 stated, its tubers made into a pulp are a substitute for soap in bleach- 

 ing. The terrified starch furnishes the British gum, or adhesive substance 

 for our postage-stamps and other labels, and for stiffening fabrics. Roasted 

 or cooked by steam, the potato is a most delicious, wholesome, and, at the 

 same time, economical vegetable aliment. By different manipulations, it 

 furnishes two kinds of starch — a gruel and a parenchyma, which in time of 

 scarcity may be applied to increase the bulk of bread made from grain, 

 and its starch is not inferior to arrowroot for the invalid. 



We often hear potato-flour spoken of, but the roots contain no flour 

 in the proper acceptation of the term ; their starch is wholly destitute of 

 gluten, a substance indispensably necessary for the production of a mass 

 of dough, which, after being duly fermented and baked, becomes bread. 



Mealy potatoes are more nutritious than those which are waxy, because 

 of the greater quantity of starch which they contain. Thus, the micro- 

 scope shows a potato to be almost entirely composed of cells, which are 

 sometimes tilled, and sometimes contain clusters of beautiful oval grains. 

 Now, these little grains remain unchanged in cold water ; but when the water 

 is heated to about the degree that melts wax, they dissolve in it, and the > 

 whole becomes a jelly, and occupies a larger space than it did in the form 

 of grains. When a potato is boiled, then each of the cells becomes full of 

 vol. n. H 



