It is raised most abundantly in Central Asia and the Himalaya.  In the latter country the different varieties are grown at various elevations, between 4,000 and 12,000 feet.  The finest samples exhibited in 1851 were from Canada, but some of excellent quality was also shown by the United States, Russia, and Belgium.  The common variety grown in Europe is the Polygonum fagopyrum, and P. emarginatum is grown in China and the East.  In this country the produce varies from 2 to 4 quarters per acre.  The quantity of seed sown is 5 to 8 pecks the acre.  Vauquelin found 100 parts of its straw to contain 29.5 of carbonate of potash, 3.8 of sulphate of potash, 17.5 of carbonate of lime, 13.5 of carbonate of magnesia, 16.2 of silica, 10.5 of alum, and 9 of water.

It is believed to be a native of Central Asia, as it is supposed to have been first brought to Europe in the early part of the twelfth century, at the time of the crusades for the recovery of Syria from the dominion of the Saracens; while others contend that it was introduced into Spain by the Moors, four hundred years before.

The cultivation of buckwheat, in one or other of its species, is principally confined to Great Britain, France, Switzerland, Italy, Netherlands, Germany, Sweden, Russia, China, Tartary, Japan, Algeria, Canada, and the middle and northern portions of the United States.

In America from 30 to 45 bushels per acre may be considered as an average yield in favorable seasons and situations, but 60 or more bushels are not unfrequently produced.

According to the census returns of 1840, the annual quantity raised in the United States was 7,291,743 bushels; of 1850, 8,950,916 bushels.

The average annual imports of buckwheat into this country have not exceeded 1,000 quarters, until last year (1852), when they reached 8,085 quarters.  A small quantity of the meal is also annually imported.

MAIZE.

Maize (Zea Mays), is the common well-known Indian corn forming one of the most important of the grain crops, and has a greater range of temperature than the other cereal grasses.  It was found cultivated for food by the Indians of both North and South America, on the first discovery of that continent, and thence derived its popular name.  Maize succeeds best in the hottest and dampest parts of tropical climates.  It may be reared as far as 40 degrees north and south latitude on the American continent; while in Europe it can grow even to 50 degrees or 52 degrees of latitude, some of the numerous varieties being hardy enough to ripen in the open air, in England and Ireland.  It is now cultivated in all regions in the tropical and temperate zones, which are colonized by Europeans.  It is most largely grown, however, about the Republics bordering on the northern shores of South America, California, the United States and Canada, the West India islands and Guiana, on the coasts of the Mediterranean, and partially in India, Africa, and Australia.  We see the singular fact in Mexico of land which, after perhaps thousands of years’ culture, is so little exhausted, that with a very little labor bestowed on it, a bad maize harvest will yield two hundredfold profit, while a good crop returns 600 fold.