AGRICULTURE 203 his time, condemning some and approving oth- ers. "A housebande cannot thryve," says he, " by his corne without cattell, nor by his cattell without corne;" and he adds, " Shepe, in myne opinion, is the most profitablest cattell that any man can have." From him it appears that marl was in common use in his day, as it had been in the island even when it was invaded by the Romans before the Christian era. Thomas Tusser's "Five Hundred Points of Good Husbandry," in a sort of doggerel verse, followed a quarter of a century later, and went through many editions. The editor of one published in 1812 says that he found difficulty in procuring a complete copy, "a proof that what was intended for practical use had been sedulously applied to that purpose. The copies were passed from father to son, till they crum- bled away in the bare shifting of the pages, and the mouldering relic only lost its value by the casual mutilation of time." Tusser mentions carrots, cabbages, and turnips, as having just been introduced as kitchen vegetables. Then appeared "The Whole Art of Husbandry," by Barnaby Googe; "The Jewel House of Art and Nature," by Sir Hugh Platt, from whom we first hear of the introduction of white clover into cultivation in England; and in 1649 ap- peared the "English Improver" of Walter Blithe (afterward revised and called the " Im- prover Improved"), a work full of judicious maxims and sound advice, giving us an insight into the prevailing practices of that time. Sir Richard Weston wrote about the same time on the husbandry of Brabant and Flanders, under the name of Samuel Hartlib, who him- self made important contributions to agricul- tural literature. But the experiments and writings of Jethro Tull, in the early part of the 18th century, are among the first important attempts at real progress in the agriculture of modern times. Writers before his time had confined themselves mainly to plain statements of the practical details of farming, recommend- ing such new practices as appeared to them worthy of adoption, and condemning the errors of their contemporaries. Tull struck out new paths of practice, invented new modes of cul- ture, and his investigations into the principles of fertility fairly entitle him to the credit of being a great original discoverer, though the errors into which he fell in his zealous enthusiasm brought more or less temporary discredit upon his whole theory. But we can excuse his mis- takes when we consider that he, like all his pre- decessors, was groping in the dark, before chem- istry and geology had made known the ele- ments of the soil and of plants, and shown how the latter derive their support and nourish- ment. Tull invented and introduced the horse hoe and drill husbandry. The latter had, in- deed, been known previously in Spain, and according to some in Germany also, but it was not known to any extent in England. He also invented the threshing machine, though the flail was almost universally used in England till the close of the last century. His doctrine that plants derive their nourishment from mi- nute particles of soil, and that repeated and thorough pulverization is therefore necessary not only as a preliminary preparation, but dur- ing the growth of the plant, led directly to the practice of drilling grain crops, and the awk- wardness and prejudice of his workmen led to the introduction of the drilling machine and the horse hoe as substitutes for hand labor. So far Tull was right in practice, however incor- rect his theory may have been. The best prac- tical farmers of the present day believe in fre- quent, deep, and thorough pulverization of the soil, not because the plant is supposed to live on minute particles of earth, but to admit air and moisture freely to the roots. Tull's theory of the nutrition of plants has not been without its followers, however, Duhamel himself having labored to spread it. Tull believed to some extent in the use of manures, but chiefly as di- viders of the soil, as a means of improving its physical texture, and not because he supposed them to furnish any nutriment to the plants themselves. His system of husbandry found very few followers at first, and those who adopted it were in many cases obliged to return to the old methods, for want of the necessary mechanical instruments for following his direc- tions ; but it has been more recently revived, mechanical skill making it practicable and com- paratively easy of application, while thorough drainage, trenching, and subsoil ploughing have gained the assent of most intelligent farmers. Even his drilling system for wheat and other grain crops has been extensively adopted in Great Britain, and is fast gaining favor. After Tull, we find little progress in agricultural lit- erature till toward the close of the last cen- tury. The chief gain in the art in the inter- mediate time was occasioned by an active competition in cattle breeding by Bakewell and others in England, which led' to the most im- portant practical results. Arthur Young, to whom perhaps the world is more indebted for the spread of agricultural knowledge than to any other man, was born in 1741, and died in 1820. His journeys to obtain information on agricultural subjects, and his writings, had a powerful influence in creating a love for agri- cultural pursuits among the learned. His searching inquiries and experiments on differ- ent soils, to ascertain the real causes of fertility (1783-'6), laid the foundation at least for more exact researches into the principles of fertility afterward. He first established the fact that common salt is a valuable manure, though it had been recommended before his day. Previ- ous to his time ammonia was thought to be in- jurious to vegetation, and natural philosophers had asserted that the food of plants was con- tained in acids. Young tried it in very many cases, and always with great success. He made experiments to learn the effect of the sun's rays on the soil, and came to the conclu- sion "that covering the soil is beneficial to it."
