198 AMERICAN AGRICULTURE. 



if three and a half feet be the distance of the hills apart, re- 

 duce the number of plants invariably to three, taking care 

 to remove those which the last plowing may have broken. 



When the seed hemp has so far advanced as readily to 

 distinguish the male from the female plants, let all the blos- 

 som hemp be cut out, except one stalk in every other hill, 

 each way. This will leave one stalk of male hemp for every 

 four hills. These, together with the stalks which after- 

 wards blossom, will be sufficient to fertilize all the seed- 

 bearing plants, and secure a crop of perfect seed. After the 

 blossom plants have remained until they have discharged 

 their pollen, which can be easily ascertained by dust ceasing 

 to flow from them when agitated, they, also, should be cut 

 down. Some top the seed plants when five or six feet high, 

 to make them branch more freely, but this is not necessary 

 where but one or two seed-bearing plants are suffered to re- 

 main in each hill." 



A seed-bearing hemp crop is a great exhauster of land, 

 whilft such as is grown only for the fibre, takes but a moder- 

 ate amount of fertilizing matter from the soil. Unlike most 

 crops sown broadcast, it grows with such strength and luxu- 

 riance, as to keep the weeds completely smothered ; and it 

 may, therefore, be grown for many successive seasons on the 

 same field, without the latter becoming foul. Its entire 

 monopoly of the ground, prevents the growth of clover or 

 the grasses in connection with it. 



The seed yields an oil of inferior value, but when cooked, 

 it affords a fattening food for animals. 



COTTON (Gossypium, FIG. 44). 



Within the last few years, this has become the leading 

 agricultural export of the United States. The total amount 

 of the cotton crop in this country, in 1845, was estimated at 

 about 850,000,000 Ibs., and for 1848, nearly 1,000,000,000. 

 This enormous product has mainly grown up within the 

 last 60 years. Even as late as 1825, our total production 

 was within 170,000,000. The introduction of Whitney!s 

 cotton gin, in the latter part of the last century, gave the first 

 decided movement towards the growth of American cotton. 

 Previous to this, the separation of the cotton seed from the 

 fibre was mostly done by hand ; and the process was so slow 

 and expensive, as to prevent any successful competition with 

 the foreign article. This incomparable invention, which 

 cleaned 1,000 Ibs. in the same time a few pounds could be 



