1877, and, on its going into effect. Prof. Johnson was appointed director. "For many years," says the Rural New-Yorker, "the station was confined to two small rooms, and the appliances and works of reference were for the most part loaned from Yale College or borrowed from the professor's private laboratory and library."
Mr. Johnson began his literary work while still a student, writing for the agricultural papers. Among the earliest of his publications of general interest was an address before the State Agricultural Society of Connecticut, in 1866, on Fraud in Chemical Fertilizers. This was followed by the adoption of measures intended to protect buyers of fertilizers against imposition through adulterations. As chemist to the State Agricultural Society he made a series of reports on fertilizers in 1857, 1858, and 1859, by means of which knowledge on the subject was extended, and frauds received a further check. Besides his official reports, "which have been models for works of their kind," Prof. Johnson's writings include many contributions to the agricultural press, which have been highly appreciated, and several books on the special subjects of his studies. The best known of these are How Crops Grow; How Crops Feed; Peat and its Uses as Fertilizer and Fuel. The earliest and best known of these books—How Crops Grow, published in 1868—embodied the results of studies undertaken by the author in preparing instruction in agricultural science. Together with its companion volume—How Crops Feed—it was intended to present concisely but fully the state of the science at the time regarding the nutrition of the higher plants, and the relations of the atmosphere, water, and soil to agricultural vegetation. In it the chemical composition of agricultural plants was described in detail, the substances indispensable to their growth were indicated, and an account was given of the apparatus and processes by which the plant takes up its food. The book was received with great favor in America and in Europe. It was republished in England under the joint editorship of Profs. Church and Dyer, of the Royal Agricultural College at Cirencester; a translation of it was published in Germany under the instigation of Prof. Liebig; and other versions of it have been made in Swedish, Italian, and Japanese, and twice in Russian.
In view of the great advance that had been made in all branches of science, a new edition of How Crops Grow was issued in 1890, in which the purpose was guarded of bringing the treatise up to date as fully as possible without greatly enlarging its bulk or changing its essential character.
The account of the sources of the food of plants, which were noticed in this volume in only the briefest manner, was reserved