200 AGRICULTUEE analyses of the ash of plants and of soils, em- ploying more perfect methods than had been previously known. It was reserved for the splendid genius of Liebig to unite the frag- ments of truth into an organic whole. The force of his rhetoric, not less than of his logic, excited intense interest in the chemistry of agriculture ; and being the most popular teach- er that this science has ever employed, he has contributed vastly to the enlistment of laborers in this important field. While Liebig discussed only "the applications of chemistry to agri- culture and physiology," his celebrated work under that title having been written at the request of the British association for the ad- vancement of science, Boussingault, a French- man of genius and wealth, occupied himself with the special study of the practical opera- ations of agriculture, and in 1842 issued his Economic rurale, a mine of valuable obser- vations and experimental results. From that time on, the number of those devoted to the study of agriculture has rapidly increased. AGRICULTURE, the art of cultivating the ground, and of obtaining from it the products necessary for the support of animal life. The change from a state of nature, in which the human race must have first lived, to the pasto- ral, or to any higher mode of living, must have been gradual, the work perhaps of ages. The race was doomed to toil, and necessity soon sharpened the power of invention. In the course of time, during which man multiplied and wandered about from place to place, the countries watered by the Euphrates, the Tigris, and the Nile were found to be most productive, and the dwellers in their valleys engaged in tilling the soil ; while the dwellers in the hilly countries of Syria and the lands east of the Mediterranean, which were better adapted to grazing, became the owners of flocks and cattle. The chief riches of the early Jewish patriarchs consisted of cattle and fruits. Chaldea and Egypt, from the remotest recorded times, were noted as the lands of corn. The fertility of the valley of the Nile, a strip of country from 7 to 8 miles in width, gradually sloping down to the river, and extending from 400 to 500 miles, is well known. It was overflowed from about the beginning of August to the end of October, and the subsiding waters left the richest possi- ble top-dressing of slime and mud. Then the cultivator had only to cast the seed, turn on a herd of swine to tread it in, and await the harvest. The agriculture of a people must be influenced by the climate and natural features of the country. Its progress must also depend in a great degree on the density of the popula- tion. The processes employed must have been extremely simple at first,being confined without doubt to merely preparing the ground for seed, without any attempt to stimulate its productive- ness. So far as we know, Egypt, Chaldea, and China were among the first nations which ex- tended the limits of agricultural practice in an- cient times. In these countries, probably, ani- mal power was first applied to agriculture ; and among the hieroglyphics on the ancient tombs of Egypt is found the representation of an im- plement resembling a pick, which was used as a plough. From Egypt a knowledge of agri- culture extended to Greece, and we find it in a tolerably flourishing state 1,000 years before Christ, if we may believe the testimony of He- siod, who describes a plough consisting of a beam, a share, and handles. We may infer that the early settlers of Sparta possessed a knowl- edge of draining, since the site of the city was surrounded by swamps and marshes, and must have been well drained before it could be made even habitable. In Greece the art of farming gradually advanced, until in the days of her glory it may be said to have attained in some provinces a high degree of perfection. The Greeks had fine breeds of cattle, horses, sheep, and swine ; many of the implements of hus- bandry in use among them were not very un- like in principle those of modern construction ; and extensive importations were made from foreign countries of sheep, swine, and poultry, for the purpose of improving the stock. The use and value of manures were known also. The Greek farmers composted with skill, and saved the materials for the compost with care. The importance of a thorough tillage was well understood by them ; they ploughed three times with mules and oxen, and sometimes sub- soiled, and often mixed different soils, as sand and clay; they cultivated the apple, pear, cherry, plum, quince, peach, nectarine, and other varieties, together with figs, lemons, and many other fruits suited to the climate. The names of Several of their agricultural writers have come down to us, though the works of only a few of them are extant, and of these the treatise of Xenophon is the most valuable. But, in comparison with many other countries, Greece was not well fitted for tillage. Agri- culture was not a source of pride with the Greeks, as it afterward became with the Rc mans. One cause of this was the fact that the land was tilled mainly by a subdued and menial race, the dominant race cultivating other arts, and caring more for building up their cities than for cultivating the soil. On the contrary, a high appreciation of agriculture seems to have been a fundamental idea among the early Ro- mans. A tract of land was allotted to every citizen by the state itself, and each one was carefully restricted to the quantity granted. It was said by the orator Curius, that "he was not to be counted a good citizen, but rather a dangerous man to the state, who could not content himself with seven acres of land." The Roman acre being about one third less than ours, the law actually limited the possession to about five acres. This, however, was only in the early days of Rome, and afterward, as the nation became more powerful, and extended its limits by conquest, the citizen was allowed to hold 50 acres, and still later he could be the holder of 500. The limitation of the freehold
