AGRICULTURE 205 ttish the elements needed by the different vari- eties of plants. "We find him in 1807 trying to ascertain the effects of various salts on barley, grass, &c., in light, sandy soils, applying twice a week diluted solutions of sulphate, acetate, bi- carbonate, and muriate of potash, sulphate of soda, and nitrate, muriate, sulphate, and car- bonate of ammonia; finding, as Young had found, that plants furnished with carbonate of ammonia grew most luxuriantly, a result which had been anticipated from the composition of carbonate of ammonia. Davy experimented on specimens of guano sent to the board of agriculture in 1805, the existence of it in large quantities on the South sea islands having been pointed out by Alexander von Humboldt. In 1806 elaborate analyses of guano were published by Fourcroy and Vauquelin. Davy, writing at this time, says: "The dung of sea birds has never been used in this country." Davy re- commended the use of bones as a manure, not so much because they contained phosphate of lime, as because they were filled with decom- posable animal matter, as gelatine, cartilage, fat, &c. But though the results obtained by Da- vy were imperfect, and in some cases erroneous, they made important advances in an almost untrodden path of investigation. The facts established by his researches as to the effect of ammonia on vegetation, may be regarded as the starting point of modern scientific investi- gations into the properties of this substance when used as a manure; for, though Young first led the way in observing its practical ef- fect on plants, his conclusions, from his want of chemical skill, had not the scientific cer- tainty which characterized Davy's, and which was necessary to give them their highest val- ue. It may indeed be said that he was the means of drawing the attention of chemists to this particular branch of their science ; for through the influence of the reputation he gained, the thoughts of other scientific men, and especially of the chemists on the conti- nent, were turned in this direction. In gen- eral, the literature of agriculture had advanced more rapidly on the continent than in Eng- land. In Germany especially many writers had treated of the subject, more particularly in works on political economy. In the latter half of the last century many treatises of prac- tical value appeared, such as those of Kretsch- mar, Reichart, Stisser, and Sprenger. At the same period Duhamel wrote in France, and adopted the views of Tull in regard to the nourishment of plants. In his treatise on the cultivation of the soil he endeavors to deter- mine the principles of agriculture by theories deduced from experiments, which subsequently received a more scientific form in the " Ele- ments of Agriculture," published in Paris in 1771. Duhamel, Buffon, and others, by their superior genius, made the study of rural econ- omy attractive to scientific men in France ; and hence there has been there more original research in agricultural chemistry, vegetable physiology, and other kindred branches, than in any other country except Germany. As early as 1730 there were 13 agricultural so- cieties in France, with about 19 auxiliary so- cieties. The survey of Franco by Arthur Young, in 1787 and 1789, also did much to ex- cite an interest in the improvement of the soil, and to make the peculiarities and wants of the country more familiarly known even to Frenchmen themselves. Merino sheep were brought into France in 1776, and kept tinder charge of the government for the improvement of the stock of the country. Bonaparte great- ly increased the number of societies, establish- ed professorships, botanical gardens, &c., all of which concurred to elevate the study of agri- culture in the estimation of those capable of bringing to its aid the principles of the ab- stract sciences; and this tendency has influ- enced the scientific minds of France to the present day, though the practice of the coun- try has not kept pace with the development of theory. This is owing partly to the division of property since the revolution, the holdings, as a general thing, being very small. The ear- liest settlers of the United States found the country a wilderness, with many varieties of climate and soil to which the knowledge they had obtained in the mother country did not apply. Thus they had to contend with innu- merable obstacles, with the wildness of nature, and their ignorance of the climate, in addition to the hostility of the Indians, the depredations of wild beasts, the difficulty and expense of procuring seeds and farming implements, &c. These various difficulties are quite sufficient to explain the slow progress they made in the way of improvement. For many years agri- culture was exceedingly backward. Stock and tools were poor, and there were obstacles arid prejudices against any " innovations " in the established routine of practice. This state of things continued for many years, with very little change. Jared Eliot, a clergyman of Connecticut, one of the earliest agricultural writers of America, published the first of a series of valuable essays on field husbandry in 1747; but, with this and a few other excep- tions, no real efforts were made to improve farming till after the revolution, when the more settled state of the country and the gradual increase of population began to im- press the intrinsic importance of the subject upon the minds of a few enlightened men. The South Carolina agricultural society was established in 1784, and still exists; and the Philadelphia society for the improvement of agriculture, established in the same year, and a similar association in New York in 1791, in- corporated in 1798, and the Massachusetts so- ciety for the promotion of agriculture estab- lished in 1792, were active in their field of la- bor, and all accomplished important results. The correspondence at this period between Sir John Sinclair and "Washington shows how anx- ious was the father of his country to promote
