THE POTATO AND ITS COMMERCIAL PRODUCTS. 103 



of it washed away by steeping in successive portions of fresh water. The 

 potatoes are easily dried. The pieces are white and of little weight, and 

 can be ground to flour and baked into bread along with the flour of wheat. 



The dry potato-starch met with in commerce is, as has already been 

 shown, far from being entirely free from moisture. The quantity of water 

 in it varies according to the temperature and the humidity of the air, but 

 generally amounts to one-fifth of the weight of the starch. It is much 

 more hygrometic than other kinds of starch, and hence not so well adapted 

 for stiffening linen, &c. 



Potato-starch is often adulterated with gypsum, chalk, and argillaceous 

 substances. Sophistication from either of these sources may be easily 

 detected by burning a small quantity of the suspected starch and incine- 

 rating the ash Unadulterated starch leaves the merest trace of earthy 

 matter. [Parnell.] 



Potatoes make a palatable bread with wheat in the proportion of one- 

 third, but one-fourth still lighter and bitter. Barley and potatoes, as well 

 as oats and potatoes, have been made into bread. In some cases the 

 potatoes were not boiled, but merely grated down into a pulp and mixed 

 with wheaten flour, in which mode it made excellent bread. It has even 

 been found that good bread may Ije made from equal quantities of flour 

 and potato-meal, which has been greatly the practice in those countries 

 most remarkable for the plentiful culture of the potato. Using the 

 potatoes after boiling, steaming, or baking, and reducing them into a sort 

 of powder, seems, however, to be the most ready method of making them 

 into bread. 



A mode has been suggested by a French chemist for converting potatoes 

 into a substance resembling coffee. He mixes some olive-oil with a 

 certain portion of dried potato-flour, and then adds a small quantity of 

 coffee-powder. He asserts that this will produce a liquor more agreeable 

 than coffee. The French have particular tastes in these matters, and are 

 always endeavouring to find substitutes for tropical products : not content 

 with chicory, so largely used, they have now acorn coffee, beetroot coffee, 

 and a dozen other coffee substitutes. 



Cheese is made from potatoes in Thuringia and Saxony. The large 

 white potatoes are boiled and peeled, and reduced to a pulp. To five 

 pounds of this pulp are added one pound of sour milk and some salt. 

 The whole is kneaded together, and the mixture covered up, and allowed 

 to lie for three or four days, according to the season. At the end of this 

 time, it is kneaded anew, and the cheeses are placed in little baskets, when 

 the superfluous moisture escarjes. They are then allowed to dry in the 

 shade, and placed in layers in large vessels, where they must remain for 

 fifteen days. The older these cheeses are, the more their quality improves. 

 Three kinds of them are made. The first, which is the most common, is 

 made according to the proportion just given ; the second, with four parts 

 of potatoes and two parts of curdled milk ; the third, with two parts of 

 potatoes and four parts of cow's or ewe's milk. These cheeses have this 



