from any operation out of the living body. We know the component parts of the food before it enters the roots; our chemists have analyzed the digested sap, and know all its properties; yet, with all this knowledge of the composition of both, no chemistry will enable us to make the one from the other: it is a process which can be carried on only in the living vessels of the living vegetable body, and which Nature refuses to unveil. In both animal and vegetable we know the original substance, and the results and the organs in which the work is done; the rest in both is equally unknown.

QUANTITY OF FOOD AND NUTRIMENT.

The daily consumption of solid and liquid food amounts, on an average, to four or five pounds for every adult. The amount of chyle which is taken up by the lacteals cannot be more than a few ounces: the rest of the food is thrown off from the body as innutritious. This is the more remarkable in animals which eat only vegetable food, which contains a less proportion of nutriment than flesh, which is the food of beasts of prey: the same is observable in men who live on vegetables or on flesh. Man is nourished, not in proportion to what he eats, but in proportion to what he digests. This is true of all the animal race, and too obvious to every one to need farther observation.

6

The same law governs the tree; and all experiments show that it consumes much more food than actually nourishes it. The quantity of the sap is not diminished in its progress from the root to the leaf; on the other hand, it is very probable that it is increased by the addition of some of the peculiar juices of the tree, thrown into it to aid its changes. But, no sooner has the sap arrived at the leaves, than a great part of it is thrown off by evaporation. The quantity thus perspired bears a very great proportion to the moisture imbibed. Mr. Woodward found that a sprig of mint weighing 27 grains, in 77 days imbibed 2558 grains of water, and yet its weight was increased only 15 grains; therefore it must have given out 2543 grains.

The same experiment was repeated by this philosopher on other plants. The following table shows the results.

These experiments demonstrate the great quantity of matter which is constantly leaving the plant. Dr. Hales found that a cabbage transmitted daily a quantity of moisture equal to about half of its weight; and a sun-flower, three feet high, transmitted in a day 1 lb. 14 oz. avoirdupois.* This transpiration is carried on through the leaves; for when these were stripped off, in the experiments, very little or no water was lost. And the quantity of the transpiration depends very much on the kind of leaf. Those which are thin and loose, with a rough surface, evaporated a great deal, while those which had leathery leaves with smooth and varnished surfaces evaporated much less.†

This evaporation consists mostly of water, leaving the nutritious portions of the vegetable food in the leaf; as the innutritious portions only of the food of the animal are thrown off, leaving the chyle, which supports the frame. But neither the chyle which is now carried to the heart,

*Thomson's Chemistry, Vol. iv.

I performed a set of experiments in July and August, 1830. I put 1000 grains of water into each of two cups, and covered one of them with a film of pig's-foot oil, and put both side by side in the sun. When the water was all evaporated from the cup containing no oil, the other cup had lost only one grain. I repeated this several times with the same result. I tried olive, whale, and neat's-foot oil, and found the loss very nearly the same; generally, however, exceeding by a very little that in the cup covered with pig's-foot oil. Presuming, then, that the loss by evaporation, if the surface were covered with the latter substance, would not essentially affect the result of the experiments, I cut branches of several kinds of trees, and

Water wasted.

TREE.

nor the digested sap in the leaf, is fit for nourishment in the plant or the animal; for before this, they must undergo another change, which is accomplished by help of the air, by the process of respiration.

immersed the ends in water covered with it, and kept them there until they began to wilt. I weighed both the branches and the water before the immersion, and again after I took them out. The following are the results of these experi

ments:

Without doubt, this evaporation was more rapid when the branch was first cut from the tree, and more feeble as it lost its vitality. The cherry was perfectly wilte when taken out: if it had been weighed earlier, it would probably have varied the result, and shown a more copious transpiration. Neither the pine nor the apple were wilted. The leaves of the latter were moist and plump.

[TO BE CONCLUDED IN OUR NEXT.]

[Furnished for the Tracts and Lyceum.]

IMPROVEMENTS IN THE ARTS.

ABOUT the year 1749, in Falmouth, now Portland, Me. a yard of calico, according to the depreciated paper currency then used, cost 35 or 40 shillings; and the wages of a laboring man were 25 or 30 shillings per day. A laboring man could then buy for his family by his day's work, only three quarters of a yard of calico; but now he can buy four or six yards. Cotton check was then 32 shillings per yard, or more than a man's wages for a day. Cambric was at the enormous price of 130 shillings per yard; or a common laboring man must work four or six days to buy one yard. Corn was at this time at 30 shillings per bushel; so that a family must give more than a bushel of corn for a yard of calico, and more than four bushels for a yard of cambric.

The improvements made in the arts have rendered such articles more abundant and cheap. A passage from the 'Working Man's Companion,' an English work reprinted in Boston 1831, will show this :- Nearly twenty years after Arkwright had begun to spin by machinery, the price of a particular sort of cotton yarn much used in the manufacture of calico, was thirty-eight shillings a pound. That same yarn is now sold for between three and four shillings, or one twelfth of its price forty years ago. If cotton goods were worn only by the few rich, as they were in ancient times, and even in the latter half of the last century, that difference of price would not be a great object; but the price is a very important object, when every man, woman and child in the United Kingdom has to pay it.' The price is now sixpence a yard; but five years ago the average price was half a crown a yard. Forty years ago, it was six shillings a yard, or twelve times its present price. About 1750, or before Arkwright's invention, the quantity of cloth manufactured could not have been equal to one five-hundredth part of that which is now manufactured for home consumption. So that thirty-one people now consume sixteen yards of cloth, where one person eighty years ago consumed one yard. We ask you, therefore, if this

vast difference in the comforts of every family, by the ability which they now possess of easily acquiring warm and healthful clothing, is not a clear gain to all society, and to every one of you as a portion of society? It is more especially a gain to the females and the children of your families, whose condition is always degraded when clothing is scanty; the power of procuring cheap clothing for themselves, and for their children, has a tendency to raise the condition of females more than any other addition to their stock of comfort. It cultivates habits of cleanliness and decency; and those are little acquainted with the human character, who can doubt whether cleanliness and decency are not only great aids to virtue, but virtues themselves. There is little self-respect amidst dirt and rags; and without self-respect, there can be no foundation for those qualities which most contribute to the good of society. The power of procuring useful clothing at a cheap price, has raised the condition of women among us; and the influence of the condition of women upon the welfare of a community, can never be too highly estimated.

F. F.

[Furnished for the Tracts and Lyceum.]

THE CHEAP TRANSPORTATION OF BOOKS AND PERIODICALS.

THE present state of society demands a cheap system of conveyance for the diffusion of knowledge. The Post Office system, is too expensive. On this system conveyance must be more expensive, from its rapidity, than is necessary for all purposes. A vast number of publications now issued, are not required to be transmitted with great speed. As mail stages now usually run, they carry a load of 1000 pounds, at three times the expense of conveying the same load at a moderate rate. 'In England,' says the Scientific Tract on Rail Roads, 'every coach on the best roads that runs for twenty four hours, at nine miles per hour, drawing not over two tons, requires no less than 180 horses, or ninety each way. Less than twelve horses would