A Mr. Penoyer, of Western Saratoga, Illinois, publishes the following, which he recommends as a perfect cure and preventive of the potato rot, having tested it thoroughly four years with perfect success; while others in the same field, who did not use the preventive, lost their entire crop by the rot.  It not only prevents the rot, but restores the potato to its primitive vigor, and the product is not only sound, but double the size, consequently producing twice the quantity on the same ground, and the vines grow much larger, and retain their freshness and vitality until the frost kills them.  Aside from the cure of the rot, the farmers would be more than doubly compensated for their trouble and expense in the increase and quality of the crop.  The remedy or preventive is as follows:—­“Take one peck of fine salt and mix it thoroughly with half a bushel of Nova Scotia plaster or gypsum (the plaster is the best), and immediately after hoeing the potatoes the second time, or just as the young potato begins to set, sprinkle on the main vines, next to the ground, a tablespoon full of the above mixture to each hill, and be sure to get it on the main vines, as it is found that the rot proceeds from a sting of an insect in the vine, and the mixture coming in contact with the vine, kills the effect of it before it reaches the potato.”  I cannot but consider Professor Bollman’s as the most important of the two remedies suggested.

The potato crop of the United States exceeds 100 million bushels, nearly all of which are consumed in the country; the average exports of the last eight years not having exceeded 160,000 bushels per annum.

According to the census returns of 1840, the quantity of potatoes of all sorts raised in the Union, was 108,298,060 bushels; of 1850, 104,055,989 bushels, of which 38,259,196 bushels were sweet potatoes.

Last year (1852) there was under cultivation with potatoes in Canada, the following extent of land:—­

Acres.                  Bushels. 
Upper Canada     77,672     Produce     498,747
Lower Canada     73,244     Produce     456,111

About 782,008 cwts. of potatoes are annually exported from the Canary Islands.  In Prussia, 153 million hectolitres of potatoes were raised in 1849.  In 1840 Van Diemen’s Land produced 15,000 tons of potatoes, on about 5,000 acres of land.

The potato is not yet an article of so much importance in France, as in England or the Low Countries, but within the last twenty years its cultivation has increased very rapidly.  It is mostly grown where corn is the least cultivated.  The quantity raised in 1818, was 29,231,867 hectolitres, which had increased in 1835 to 71,982,814 hectolitres.  About 2,000,000 hectolitres of chesnuts are also annually consumed in France, a portion of the rural population in some of the Central and Southern Departments living almost entirely on them for half the year.