Triumphs and Wonders of the 19th Century: The True Mirror of a Phenomenal Era / A volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress

by James P. Boyd

VII. AGRICULTURAL CHEMISTRY.

Sir Humphry Davy, in the beginning of the century, delivered a course of lectures on the relations of chemistry to agriculture, and these were published in book form. In France, important contributions were made to agricultural chemical science by Vauquelin, Chevreul (1786–1889), and Boussingault (1802–1887), who made important researches before the middle of the century. The most important work in agricultural chemistry, however, was done by Liebig. His achievements so overshadowed those of his predecessors that he is generally regarded, although improperly, as the father of that branch of the science.

The early achievements of these workers showed the relatively small portions of the crops that were derived from the soil. The study of the ash constituents of plants laid the foundation of rational fertilizing, and the utilization of the stores of plant food preserved in great natural deposits.

Beginning with the middle of the century, the attention of agronomists was called to the desirability of utilizing the deposits of guano, found in the islands along the west coast of South America; of the deposits of phosphate rock existing in many localities; and later, of the potash salts, discovered near Stassfurt, which completed the trio of available natural foods most useful to plants.

The establishment of an agricultural experiment station by Sir John Lawes at Rothamstead (1834), before the middle of the century, set an example which has been followed by the establishment of experiment stations in all the civilized countries of the world.

Under the great stimulus given to agricultural research by these stations, progress during the latter half of the century has been very rapid. There now exist in Europe nearly one hundred stations devoted to agricultural research, and in this country the number is half as great.

Conspicuous achievements, marking the closing years of the century, have been the discovery of the methods whereby organic nitrogen is rendered suitable for plant food, and atmospheric nitrogen fixed and rendered available by leguminous plants. In the first instance, it has been established that organic nitrogen in the soil can only be utilized by plants after it has been oxidized by bacterial action. In the case of leguminous plants, nitrogen is rendered available for nutrition by means of bacteria inhabiting nodules in the roots of the legumes. These two great discoveries have proved of incalculable benefit to practical agriculture. Chemical science in its relations to agriculture has shown that the fertility of the soil may be conserved and increased, while the magnitude of the crops harvested is sustained or augmented. Thus, no matter how rapid may be the increase of population, agricultural chemistry will provide abundant food.