278 MAI/K. 



Carbonic acid and nascent hydrogen evolved in rotting stable 

 manure are truly valuable food for plants, and perform important 

 chemical offices in the soil ; but they are, nevertheless, not so 

 indispensable to the economical production of crops, as available 

 nitrogen, potash, silica, magnesia, sulphur, and phosphorus. 

 These elements of plants being less abundant in nature, and 

 quite indispensable in forming corn, cotton, and every other 

 product of the soil, their artificial supply in guano, night soil, 

 and other highly concentrated fertilisers, adds immensely to 

 the harvest, through the aid of a small weight of matter. In all 

 sections where corn is worth 30 cents and over a bushel, great 

 benefits may be realised by the skilful manufacture and use of 

 poudrette. This article is an inodorous compound of the most 

 valuable constituents of human food and clothing. It is the raw 

 material of crops. 



It is not necessary to restore to a corn-field all the matter re- 

 moved in the crop to maintain its fertility. A part of each seed, 

 however, ought to be carried back and replaced in the soil, to make 

 good its loss by the harvest. 



In every barrel of meal or flour sent to market (196 pounds), 

 there are not far from 186 pounds of carbon (coal), and the ele- 

 ments of water. When a bird eats wheat or corn, I have reason 

 to believe, from several experiments, that over 80 per cent, of the 

 food escapes into the air through its capacious lungs in the process 

 of respiration ; and yet the 20 per cent, of guano left will re- 

 produce as much wheat or corn as was consumed. Imported guano, 

 which has been exposed to the weather for ages, often gives an 

 increase in the crop of wheat equal to three pounds of seed to one 

 of fertiliser ; while it has given a gain of seven to one of corn, and 

 fifty to one of green turnips. 



Like other grains that have been long cultivated, Indian corn 

 abounds in varieties. In Spain they count no less than 130, and 

 in the United States the number is upwards of forty. The differ- 

 ence consists in size, color, period of maturation, and hardness and 

 weight of grain. Of size there exists a considerable variety, from 

 Zea Curagua of Chili, and the Egyptian or chicken corn, both 

 extremely diminutive, to the large white flint, and ground seed 

 corn of the United States. The differences in color are the red, 

 yellow, and white. The period of maturation varies, apparently, 

 very considerably ; but it is questionable whether this variation 

 is real, and independent of climate. In the Northern States of 

 America. Indian corn ripens in a shorter period of time than it 

 does in the South, owing, possibly, to the greater length of the 

 summer day in those latitudes. 



In selecting varieties, some experienced and judicious farmers 

 prefer that which yields the greater number of ears, without regard 

 to their size, or number of rows. Others prefer that which furnishes 

 one or two larger ears, having from twelve to twenty-four rows. In 

 the Northern States of America the yellow corn bears the highest 

 price in the market, and is considered the most prolific and 



