Fumigation of the cow-house is resorted to as one of the means of preventing the spread of abortion: tar, sulphur, gunpowder, feathers, and the like, are burned for the purpose of destroying the odour. We have never seen a single instance of the practice being attended with the smallest success; while it is obvious that, if carried beyond a certain point, it may produce the very evil it is intended to remove or mitigate.

or other causes affecting their growth. Thus fruit often becomes abortive, in consequence of cold winds or frosts in spring checking the flow of the nutritive juices; and after losing its healthy colour it shrivels, and falls. The same effects arise when the leaves of fruitbranches are devoured by caterpillars, or the fruit-stalks sucked by insects (Aphides, Cocci, &c.). The only preventives are sheltering from cold, and destroying the insects.

ABSCESS (Latin, abscessus). In veterinary surgery, a circumscribed cavity in an animal, containing matter. [In common language, an imposthume or gathering.] The deposition of matter in a solid part of the body is always preceded, and in some degree accompanied, by inflammation. The local symptoms are, pain on pressure, heat, swelling, hardness, and, where it can be seen, redness. These are easily recognised, in proportion as the inflamed part is near the external surface. If the part in which an abscess is about to form be soft, yielding, and well supplied with blood, it soon softens and points, the pain di

nant cows.

If the signs of approaching abortion be discovered early, the accident may sometimes be prevented. If the cow is in good condition, then immediately let it be bled to the extent of five or six quarts, and the bowels opened with half a pound of Epsom salts, three or four drams of aloes in powder, or as many ounces of castor oil, administered in a quart of gruel; but if the cow is in very poor condition, and the miscarriage is anticipated from her having been exposed to cold, it would be more advantageous to avoid bleeding, and give her a warm gruel drink, with an ounce of laudanum in it. If after this abortion does take place, let her be kept in a comfortable place by herself; and if the after-birth has not passed off, let no injudicious and unnecessary administration of violent forcing medicines, such as capsicum or hellebore, be given. Nature, with a little assistance, is generally equal to the perfect restoration of the animal.

Abortion in the Sheep. Ewes are much subject to abortion, in consequence of the numerous accidents they are liable to, such as fright, overdriving, being worried or run with dogs, a remarkable instance of which came under my own observation. A pack of hounds, in pursuit of a hare, got among a flock of sheep belonging to a farmer, and so hurried and alarmed them, that thirty out of a flock of two hundred ewes prematurely dropped their lambs. It is the same in sheep as in the other cases of domestic animals,-scarcity of food, and exposure to severe cold, having a great tendency to make the ewes prematurely drop their lambs, or produce them weakly and crippled at the full time; and although there may be a little danger in giving too much food, such as allowing them to feed all the winter on turnips, the danger is trifling compared with the starving system. (Miller.)

ABORTIVE. A term applied by gardeners and farmers to flowers, seeds, and fruits, which

fluctuating under it, and by and by the skin bursts, or a portion of it drops out, and the matter escapes. What is called the process of granulation succeeds to this; and, provided the matter be completely evacuated, and the outlet be such as not to retain any that may form subsequently, the cavity soon fills up.

Such are the different stages of an ordinary abscess. The general health of the animal is rarely affected; but if an abscess form in a dense unyielding texture, in a part which cannot without much difficulty accommodate itself to an increase of volume, then the swelling may be less, but the animal will endure a great deal more pain, [as is often exemplified under similar circumstances in the disease called felon or whitlow in the finger or human hand.] The irritation, indeed, is sometimes so great, from this cause, as to induce fever, and even death; and hence the formation of an abscess in the foot of an irritable horse is not an unfrequent cause of death. During the deposition of the matter in such cases, we have general symptoms added to those termed local. There is loss of appetite, thirst, a hot skin, quick and hard pulse, constipated bowels; in short, the animal is fevered. When an abscess forms in a part remote from the surface, its presence is not easily recognised. The general practitioner has here an advantage over the veterinary surgeon. The expressed feelings of the patient, and the occasional slight shivering fits which accompany the formation of matter, are guides which the veterinary surgeon rarely or never command. The shivering, if it occurs, passes unobserved, and the animal can give no account of himself; dissection, therefore, sometimes reveals large abscesses, whose existence was not even suspected dur ing life. Fortunately these are not frequent.

can

It is a curious circumstance, and one that well illustrates the preservative principle of a living being, that, unless there be some me

sore.

ABSORPTION. An important process in vegetable physiology. As plants are not furnished with any individual organ similar to the mouth of animals, how, it may be asked, do they effect the introduction of food into their bodies; Is it by the general surface of their stem, leaves, or roots, or by any peculiar part of these? By whatever part it may enter, it must, at any rate, pass through the covering of the outer bark (epidermis), which the earlier physiologists thought it could not do, but by means of pores more or less visible. Yet some of them describe the outer bark as being so close and compact a texture, that the eye, aided even by the best microscopes, was unable to discover in it the slightest vestige either of pores or of apertures. But Hedwig and De Candolle detected superficial pores in the leaves, at least, of many plants; and so will any one else, who will be at the trouble of repeating their observations with lenses of similar powers.

The next difficulty was with regard to the outer bark (epidermis) of the flower, fruit, and root. No pores had been detected in the flower and fruit, though it was evident that they were refreshed and invigorated by the access of moisture and of atmospheric air; and no pores had been detected in the root, though it was evident that the whole of the nourishment which the plant derives from the soil must of necessity pass through the root. It was also evident that no aliment could be taken up by the plant, except in the state of a liquid, or of a gass-that is, by absorption or by inhalation, as the chyle is taken up into the animal lacteals, or the air into the cells of the lungs. The greediness with which plants absorb water was perceived and acknowledged even in the earliest times, and even by men who were not botanists. Anacreon, in one of his little trifles in honour of drinking, makes the very trees of the forest drink:

Ἡ γῆ μέλαινα πίνει, Πίνεν δὲ δένδρες αὐτήν. Ode xix. "The black earth drinks, and the trees drink it ;" that is the moisture which it contains.

By merely immersing in water a plant of almost any species of moss that has been some time gathered, or long exposed to

It might be doubted whether any of the moisture thus imbibed had passed through the root. But if the bulb of a hyacinth is placed on the mouth of a glass bottle filled with water, so as that the smaller roots (radicles) only shall be immersed, the water is imperceptibly exhausted, and the plant grows. The moisture must, consequently, have passed through the root. Plants seem, indeed, to be peculiarly well adapted for the absorption of fluids by the roots, from the infinite number of little absorbent fibulous sponges (spongiola), in which the fine fibres of the root terminate. owing to this important property that the scientific gardener, in the transplanting of his young trees, or the scientific and ornamental planter, in the transplanting of his trees of full growth, is so extremely careful to preserve entire even the minutest fibres and extremities of the root. Sir Henry Steuart's Planter's Guide has taught him the great importance of these little organs.

It is

Hales instituted a variety of experiments to show the absorbing power of roots, and the force with which it acted; as did also Duhamel and Marriotte, to show the absorbent power of leaves. But the most complete set of experiments upon the absorbent power of leaves is that of M. Bonnet, of Geneva, whose main object was to ascertain whether the apsorbing power of both surfaces of a leaf was alike. With this view he placed a number of leaves over water, so as that they only floated on it, but where not immersed; some with the upper surface, and others with the under surface, applied to the water. If the leaf retained its verdure the longer with the upper surface on the water, the absorbing power of the upper surface was to be regarded as the greater; but if it retained its verdure the longer with the under surface on the water, then the absorbing power of the under surface was to be regarded as the greater. Some leaves were found to retain their verdure the longer when moistened by the upper surface, and some when moistened by the under surface; and some were indifferent to the mode in which they were applied to the water. But the inference deducible from the whole, and deduced accordingly by Bonnet, was that the leaves of herbs absorb moisture chiefly by the upper surface, and the leaves of trees chiefly by the under surface. What is the cause of this singular difference between the absorbing surfaces of the leaf of the herb, and of the tree? The physical cause might be the existence of a greater, or of a smaller number of pores, found in the leaves of the herb and tree respectively. The chemical cause would be the peculiar degree of affinity existing between the absorbing organs and the fluid absorbed. Duhamel seems to have been content to look to the physical cause, merely regarding the lower surface of the leaf of the tree as being endowed with the greater

capacity of absorbing moisture chiefly for the purpose of catching the ascending exhalations which must necessarily come in contact with it as they rise, but which might possibly have escaped if absorbable only by the upper surface, owing to the increased rapidity of their ascent at an increased elevation; and regarding the upper surface of the leaf of the herb as being endowed with the greater absorbing power, owing to its low stature and the slow ascent of exhalations near the earth. This did not throw much light upon the subject; and the experiments were still deemed insufficient, as not representing to us the actual phenomenon of vegetation, though the fact of the absorption of moisture by the leaf is fully confirmed.

roots.

If, after a long drought, a fog happens to succeed before any rain falls, so as to moisten the surface of the leaves, plants begin to revive, and to resume their verdure long before any moisture can have penetrated to their Hence it follows incontestibly, either that moisture has been absorbed by the leaf, or that exhalation has been suddenly stopped by closing the pores of the leaf, or both. The efficacy of rain and of artificial waterings may be accounted for partly on the same principle; for they have not always penetrated to the root when they are found to have given freshness to the plant by either or both of the processes just alluded to. The moisture, then, that enters the plant as an aliment, is taken up by means of the pores; or, in default of visible pores, merely by means of the absorbent power of the outer bark (epidermis), not only of the root and leaf, but often, as it is to be believed, of the other parts of the plant also, at least when they are in a soft and succulent state.

It is to the modern improvements in pneumatic chemistry, and to them alone, that we are indebted for our knowledge of the real functions of the leaves of plants, and of their analogical resemblance to the lungs of animals, it being now proved indisputably that the leaves of plants not only contain air, but do both inhale and respire it. It was the opinion of Dr. Priestley that they inhale it chiefly by the upper surface; and it has been shown by Saussure that their inhaling power depends entirely upon the integrity of their organisation. A bough of Cactus Opuntia, detached from the plant and placed in an atmosphere of common air, inhaled in the course of a night four cubic inches of oxygen; but when placed in a similar atmosphere, after being cut to pieces and pounded in a mortar, no inhalation took place. The inhalation of air, therefore, is no doubt effected by the pores of the outer bark (epidermis) of the leaf.

It is important to attend particularly to the distinction pointed out above, that it is not the whole of the root which is endowed with the power of absorbing nourishment, but only the points of the root fibres, termed spongelets. The surface of the root whose outer bark has acquired a certain consistence does not absorb the moisture of the soil in contact with it; but the roots, and also the smallest rootlets, constantly lengthen at their extremities; and these extremities are composed of a fine cellular

tissue, compact, spongy, and the whole newly developed, possessing in a high degree the hygroscopical faculty proper to vegetable tissue.

M. Carradori (Degli Organi Assorbenti) has remarked that there is a slight absorption, either by the surface of the roots, or by the fugacious hairs with which the roots of young plants are often furnished: but this effect seems owing to general hygroscopicity; and he himself agrees that this absorption is extremely feeble, especially in old and woody roots, comparatively with that which takes place at their extremities. These experiments, however, are not made with such minute accuracy as to enable us to appreciate this comparison.

When we cut a branch of a tree and plunge it into water, its woody tissue thus laid bare quickly absorbs a quantity of water; and in this manner is the life of branches preserved which are kept for ornamental purposes, but this effect has a limit. The extremity which has been cut and plunged in the water is not renewed, as in the case of the root; and is, consequently, more or less quickly altered or deteriorated by being in contact with the water. We renew its action by cutting off the rotting extremity, and thus place a new and healthy surface in contact with the liquid. The water which in this manner penetrates into the woody tissue of vegetables, preserves their existence, at least for a certain time, as if it entered by the spongelets. This is the same thing, we may rest assured, in these phenomena, as is presented in the developement of the cuttings of trees, which are also nourished in general only through the water sucked up by the surface of their denuded wood. These means of nutrition are, however, accidental or artificial; and absorption is a natural operation by the spongelets in general, or by the suckers in some vegetable parasites. M. Sennebier observed that, if we divide a plant into three parts, the roots as far as the crown, the stem as far as the branches, and the leafy top, then plunge the lower ends of these into water, the whole three will pump up a certain quantity, but the leafy parts more than the others. This absorption particularly takes place at the cut surface, where the woody parts are laid bare.

A branch of raspberry put in water and ex posed to the sun has absorbed a hundred and fifty grains, but only imbibed eight grains when the division has been covered over with wax. It sucked up no more when, having the divided part covered, it was plunged in the whole of its length, than when only a short zone at the extremity was immersed. This proves that the outer bark is impenetrable to water.

The woody portion, when laid bare, sucks up moisture in every way; that is to say, when we cut a branch and place it in the water, it sucks it up, either when put into it by the upper or by the lower cut part. The habitual or upright direction, however, appears to offer certain facilities for this more than an inverse one. This, indeed, results, first, from the observation of M. Pollini (Elem. di Botan., i. 281); for the watery juices mount a little less high