PART III. RATIONALE* OF THE ARTS. HAVING Completed our sketch of the principal agents employed in the Arts, as well as of the machinery by which they are applied to various uses, we proceed to consider the Arts themselves. It will be our object to state, perspicuously but briefly, the most important principles applicable to each art, and the influence which has been exerted by science, in facilitating and improving its various operations. We shall also endeavor to keep steadily in view, the great ends, to which all improvements should be directed, and to suggest some means, by which their progress might be hastened. The task is evidently too extensive for a work like the present; and the Author will feel amply satisfied, if he can succeed in presenting any views, which are calculated to awaken inquiry among the laboring classes, or to invest with interest, to the miscellaneous reader, a subject so obviously important, and yet so generally neglected. He proposes to consider, in the order here indicated, the following Arts: I. Agriculture. II. Architecture. III. Cloth Manufacture, including Dyeing, Bleaching, and Paper-making. IV. The Domestic Arts, including Brewing, Distilling, and Wine-making. V. The Arts of Working Metals. VI. The Manufacture of Glass and Porcelain. VII. The Arts of Copying. VIII. Locomotion. IX. Some reflections on the progress of the Arts, past, present, and to come. X. Influence of the Arts on National Welfare. * That is, an explanation of the principles. CHAPTER I. AGRICULTURE. THIS has justly been termed the parent of all the arts. The art first practised by mankind; the one from which they derive the means of subsistence; and which is connected, therefore, most intimately with the comfort of all; forming the occupation, too, of a large majority, in every civilized country,* and exerting upon their health, happiness, and moral habits, the most beneficial influence; it must ever occupy the highest place in the estimation of the statesman and philanthropist. We assign it this place, however, not so much on account of its importance, as because it serves to illustrate, in a striking manner, the dependence of the arts on chemical and physical science. In as far as Agriculture proposes to improve the natural productiveness of the soil, it must derive its principles chiefly from chemistry. In as far as it proposes to plough, sow, and perform the other processes of husbandry, with the least possible labor, it must be indebted to mechanics.† It appears, then, that there are two branches of Agriculture, which will successively call for our attention,Chemical and Mechanical. I. Chemical Agriculture.—One of the first objects of the husbandman is, to increase the natural productiveness of the soil. Few soils possess, by nature, a * In England, it is otherwise. It has been computed, that not more than one third of the inhabitants of that country are employed in husbandry. In every other country, the proportion is much larger. In France, two thirds; in Italy, a little more than three fourths; and in the United States, not much less than five sixths. † Our limits do not permit us to explain the application to Agriculture of other sciences. It must be obvious, however, that, in order to deal with plants, we ought to know something of their structure, properties, and use; and this we learn from botany. In that branch of husbandry which relates to animals, we require some knowledge of animal physiology and medical science. sufficient supply of those substances which form the food of plants; and where they do possess such a supply, they would still, unless properly treated, soon become exhausted, by culture. Hence the importance of providing artificial means for improving or sustaining the productive qualities of the soil. These means consist in fallowing, green crops, convertible or alternating husbandry, burning, irrigation, and manure. To which of these the farmer shall resort, in any given instance, is an all-important question; and one which he cannot easily settle, without the aid of chemistry. If land be unproductive, there must be some defect in the constitution or condition of the soil; and oftentimes this defect can only be discovered by chemical analysis. Does this analysis show that the soil contains some noxious principle, such as the salts of iron? Chemistry teaches how this principle may be decomposed, by means of lime. Is it asked, what kind of limestone should be employed, in any given case? A simple chemical test will enable us to resolve the doubt. The value of chemistry will become more apparent, however, if we attend a little to the rationale of agriculture. It has been found, by careful observation and experiment, that the principal food of plants is carbonic acid gas, atmospheric air, and the humates of potass and lime; all which are mixed with water, and presented to the suckers, at the tip of the root-fibres, to be thence carried into the interior of the plant. The first two are also taken in through the leaves. The carbonic acid gas is necessary, in order to supply the carbon which forms the solid or woody fibre of the plant. The atmosphere is needed, partly in order to supply azote, which is a chief ingredient in the gluten of wheat, in starch, and various plants, and partly in order to supply oxygen. The humates of potass and lime are necessa A humate is a compound, formed by the union of potass or lime with humic acid. Humic acid is more generally known in the books by the name of ulmic acid. ry, because the humic acid (in addition, doubtless, to other important uses which are not well understood,) renders soluble the lime and potass, which must enter more or less into the composition of all plants, and are in some the principal constituents. These, then, being the food of plants, it becomes the object of the farmer to procure the most ample supply of them. In the wise economy of Nature, large quantities of these substances are constantly generated. Carbonic acid is continually thrown out, by the respiration of animals, and by the combustion and putrefaction of vegetable substances. The different parts of the atmosphere are mingled together by winds or changes of temperature, and are successively brought into contact with the surface of the earth, so as to exert their fertilizing influence; while potass and lime, together with humen,* form a large part of the substance of the earth. Ample magazines of the food for plants having been thus provided, a principal office of the husbandman consists in collecting and applying it to the soil under his care. It must be remembered, that none of these principles are taken into plants at the root, except when mixed with water. The first object, then, to be attended to, in agriculture, is, to have the soil supplied with water, and to have this water minutely diffused through its mass. This is effected, in part, by dividing the soil, with the plough and harrow, so that the rain may enter, and be circulated, while superfluous water is allowed to escape by evaporation. Another mode of carrying off superfluous water, while it serves to supply the necessary moisture to the soil, is draining, which, in this country, is not sufficiently appreciated. Care must be taken, * A name, given to the substance yielded by the decomposition of vegetable or animal matter. It is a black or brown powder, called, by Davy, "a peculiar extractive matter of fertilizing quality," and which the chemists of France have denominated terreau. + It is not unlikely that water, besides being a purveyor of food for plants, is itself an aliment. Hydrogen forms a large part of many plants. however, lest the water, in its circulation, move so rapidly, that the roots cannot take up the nutritive principles which it contains. On the other hand, it may move too slowly, so as to choke up the mouths of the small vessels, or it may, by deposition, lose its nutritive properties. It is also necessary that the quality of the subsoil should be attended to; as, in cases where this soil consists of stiff clay, or marl, or rock lying in a horizontal position, the water settles, and remains stagnant.* After thus providing for the proper diffusion of water through the soil, the next duty of the husbandman is, to see it supplied with the necessary quantity of carbonic acid gas, and of the humates before mentioned. The first of these substances is produced, not only by the respiration of animals, but also by the decomposition of vegetable and animal substances; from which decomposition, the humic acid is also freely formed. Now, in order to procure this supply of vegetable matter for decomposition, we may, in the first place, allow land to lie fallow, by which, the crop of weeds will rot, and form a vegetable mould; or, secondly, we may raise green crops, as they are called, consisting of buckwheat, clover, pease, &c., which are to be ploughed in, while standing, and before they are ripe; or, in the third place, we may apply vegetable and animal manures, in which the process of decomposition has already commenced. The last two of these methods are much preferable to the first, which is now little followed.† *There are three kinds of drains,-open, under, and furrow, drains. The under have a great advantage over open drains, in point of durability, efficiency, and ultimate cheapness. They are not enough used, by American farmers. The furrow drain is of recent introduction, and is hardly known, except in Scotch and English husbandry. The field is laid into ridges, of twenty or thirty feet broad, in the direction of its slope, and under-drains are laid in every central furrow. "Fallowing," says Chaptal, "was necessary, as long as grains only, all of which exhaust the lands, were cultivated. But at this day, when we have succeeded in establishing the cultivation of a great |