In Peru dried potatoes are thus prepared:—­Small potatoes are boiled, peeled, and then dried in the sun, but the best are those dried by the severe frosts on the mountains.  In the Cordilleras they are covered with ice, until they assume a horny appearance.  Powdered, it is called chimo.  They will keep for any length of time, and when used required to be bruised and soaked.  If introduced as a vegetable substance in long sea voyages, the potato thus dried would be found wholesome and nourishing.  A large and profitable business is now carried on, in what is called “preserved potatoes,” for ships’ use, prepared by Messrs. Edwards and Co., which are found exceedingly useful in the Royal Navy, in emigrant ships, for troops and other services, from their portability, nutritious properties, and being uninjured by climate.

Few persons are probably aware of the quantity of potatoes used in England, America and the Continent, in the manufacture of starch, arrowroot, and tapioca, &c., A starch manufactory in Mercer, Maine, United States, grinds from 16,000 to 24,000 bushels annually of potatoes, and makes 140,000 to 240,000 lbs. of starch, which finds a ready market at Boston, at four dollars the hundred pounds.  The New England manufacturers prefer it to Poland starch.  Another starch manufacturer, in Hampden, America, consumes 2,500 bushels per day.  In a single district in Bavaria, in Germany, 400,000 lbs. of sago and starch are manufactured from potatoes; 100 lbs. of potatoes are said to yield 12 lbs. of starch.  From experiments made in America, with three varieties of potatoes, the long reds, Philadelphia, and pink-eyes, it was found that the former yielded the most starch, viz., about 6 lbs. to the bushel.  A bushel of potatoes weighs about 64 lbs.  The following table from Accum, gives the rate of starch and component parts per cent. in different varieties:—­

+-------------------+--------+-------+---------+------+

---------+------+
|       Sort.       |Fibrine.|Starch.|Vegetable| Gum. |Acids and|Water.|
|                   |        |       | Albumen.|      |  Salts. |      |
+-------------------+--------+-------+---------+------+-----

----+-------
|Red potatoes       |   7.0  |  15.0 |   1.4   |  4.1 |   5.1   | 75.0 |
|Ditto germinated   |   6.8  |  12.2 |   1.3   |  3.7 |         | 73.0 |
|Potato sprouts     |   2.8  |   0.4 |   0.4   |  3.3 |         | 93.0 |
|Kidney potatoes    |   8.8  |   9.1 |   0.8   |      |         | 81.3 |
|Large red ditto    |   6.0  |  12.9 |   0.7   |      |         | 78.0 |
|Sweet ditto        |   8.2  |  15.1 |   0.8   |                | 74.3 |
|Potato of Peru     |   5.2  |  15.0 |   1.9   |     1.9        | 76.0 |
|Ditto of England   |   6.8  |  12.9 |   1.1   |     1.7        | 77.5 |
|Onion potato       |   8.4  |  18.7 |   0.9   |     1.7        | 70.3 |
|Voigtland          |   7.1  |  15.4 |   1.2   |     2.0        | 74.3 |
|Cultivated in the  |        |       |         |                |      |
|  environs of Paris|   6.8  |  13.3 |   0.9   |  3.3 |   1.4   | 73.1 |
+-------------------+--------+-------+---------+------+---------+------+

The first six varieties were analysed by Einhoff, the next four by Lamped, and the last named by Henry.