1847.] Agricultural Chemistry. 147 



AGRICULTURAL CHEMISTRY. 



The Three Kingdoms of JVature adapted to each other — Liebig's 

 doctrine of Vegetable nutrition considered — Facts against it — 

 Improvement of soils — Rules — Scientific Agriculture — Neces- 

 sity of an extensive Atmosphere. 



1. The adaptation of the animal, vegetable, and mineral king- 

 doms to each other, is one of the most beautiful instances of de- 

 signing mind and controlling power. In the mineral kingdom 

 are treasured up the elements which enter into the composition of 

 vegetable matter. Besides the carbon, oxygeii, hydrogen, and 

 nitrogen, the four great constituents of vegetables, the earth con- 

 tains the other varying elements, as potash or soda, lime and mag- 

 nesia, common salt and iron, and silica, phosphoric acid, &c., 

 called inorganic substances. Besides giving the adequate support 

 of plants, the roots spread themselves into the midst of the great 

 storehouse of these latter substances. Constituted as the vegeta- 

 ble kingdom is, the roots become the only possible way of bring- 

 ing these substances into the vegetable structure. When the 

 necessary quantity of these substances, or of any one of them, is 

 wanting in the soil, vegetation suffers; and the art of agriculture 

 consists in supplying the deficiency, as the science reveals what 

 element is wanting. 



2. The vegetable kingdom is the great source of nutriment to 

 the animal. It elaborates the albumen, fibrin, and caseine, which 

 are the substances essential to the maintenance of animal life; 

 while both animal and vegetable matter yield, in their decay, to 

 the mineral kingdom, the elements for the repetition and continu- 

 ance of this process. 



3. By respiration, animals take up the oxygen of the atmo- 

 sphere, and return it united with carbon, in the form of carbonic 

 acid. By means of combustion, fermentation, and the like, the 

 quantity of carbonic acid in the atmosphere is greatly increased. 

 But this acid is the support of plants; for it is taken up by the 

 leaves and bark, and roots; and its carbon goes to form the vari- 

 ous vegetable substances, w^hile its oxygen is discharged for the 

 special use of the animal kingdom. Thus the atmosphere is made 

 pure, for the support of animal life, and the vegetable receives one 

 of the essential parts in its composition. The adaptation to each 

 other is thus splendidly shown in these two kingdoms. The at- 

 mosphere is deteriorated by various chemical and chemico-animal 

 processes, and is purified again, and constantly, by cheraico-vege- 

 table operations. 



4. Another substance, ammonia, is considered essential to the 



