Lectures on the applications of chemistry and geology to agriculture / by Jas. F.W. Johnston.

  • James Finlay Weir Johnston
Date:
1851
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Licence: Public Domain Mark

Credit: Lectures on the applications of chemistry and geology to agriculture / by Jas. F.W. Johnston. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    practising from the most remote ages, and in the most skilful manner, various arts which the progress of modern science has but recently in- troduced into civilized Europe; cultivating their soil with the most assid- uous labour, and stimulating its fertility by means which we have hith- erto neglected, despised, or been wholly ignorant of—but which the dis- coveries of the present time are pointing out as best fitted to secure the amplest harvests—and have thus been enabled to compel their limited soil to yield a sufficient sustenance to its almost unlimited population.* Experience and example, therefore, encourage us to look forward to still further improvements in the art of culture, and, independent of such as may be derived from purely mechanical principles, theoretical cnemistry seems to point out the direction in which important advances of another kind may reasonably be anticipated. The Chinese are said to be not only familiar with the relative value and efficiency of the va- rious manures, but also to understand how to prepare and apply without loss that which is best fitted to stimulate and support each kind of plant. How far this statement is exaggerated we are unable at present to de- termine, but it is in this direction that chemistry appears likely to pro- mote the advance of European agriculture. The practical farmer al- ready rejoices in having in one ton of bone dust the equivalent of 14 tons of farm-yard manure; some of the most skilful living chemists predict that methods will hereafter be discovered for compressing into a still less bulky form the substances required by plants, and that we shall live to see extensive manufactories established for the preparation of these condensed manures.f * An intelligent correspondent reminds me that the agricultural skill of the Chinese is questioned by recent writers on the customs of that country. This doubt is founded chiefly on the rudeness of their agricultural implements and the scarcity of cattle, whether horses or cows, among them. But in this densely peopled country the hoe they employ serves the purpose of every other implement (Davis's China, ii. 282). and where the place of cat- tle is supplied by an equivalent number of men, there can be no comparative want of valuable manure. The population of China, however, is probably not so dense in all the provinces as it has hitherto been supposed. Many writers have estimated the entire population at 300 millions, while recent statists reduce it to 175 millions. Taking even the higher estimate, the population is not more dense than in England and Holland—the area ofChina proper being 1,200,000 square miles, or eight times that of France. It is considera- bly less dense, indeed, if we take into account the number of horses and cattle which in Europe are reared and fed on the produce of the land. We may hereafter expect more ac- curate information, however, especially regarding the interior of this interesting country.— See Ajipendix A. 1 Should the opinions above expressed appear too sanguine to some, or be treated by any of my readers as merely theoretical, I would refer them to the words of Mr. Smith ofDean- ston, the inventor of the subsoil plough, and the introducer of the greatest practical im- provement in modern agriculture. After stating that at least three-fourths of the ithole ara- ble land in the country is under very indifferent culture, chiefly from the want of complete draining and deep working, and, adverting to the increased produce it may be made to yield, lie says, '■' it is not afall improbable that Britain may become an exporting country in grain in the'course of the next twenty years.—Remarks on Thorough Draining and Deep Ploughing, l>y James Smith, Esq., of Deanston Works, p. 22. Were the population to remain stationary, Mr. Smith may be right; at all events, this opinion shows that even practical men d'o not despair of attaining to a pitch of improvement in agriculture which theoretical writers dare not venture to predict. But amonc all persons of enlarged information a similar opinion prevails. Thus the eloquent author of a recent work on the principles of population says, the single alteration of substituting the kitchen-carden husbandry of Flanders in our plains, and the terraced cullure of Tuscany in our hflls, for the present system of agricultural management, would at once double tin-' produce of the British islands, and procure ample subsistence for twice the number of its present inhabitants.—Alison's Pri/Kiples of Population, I. p 216. These hopes are not to be rejected or suppressed ; for, though they may never be fully realized, yet they are, as it were, the seeds of exertion, from which ample harvests ol good may hereafter be reaped.
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