dustrious insects to change their habitation. The nests of those wasps which build in the earth may be destroyed with hot water or oil; those on trees are best suffocated by lighted brimstone. (Kollar on Insects, p. 79.) Wasps are much affected by cold; so that when winter begins to set in they become less bold and savage, and they all perish, except a few females, as soon as the frost begins. This is a wise provision of nature; for, did they survive the winter, they would soon rival the locust in their destructive depredations. WASTE LAND. The following is an account of the quantity of land uncultivated and waste in the British dominions, including Scotland, Ireland, and the British islands, according to the evidence of Mr. Cowling before the Emigration Committee in 1827 :- with which they experimented, or guarding with rigid accuracy against other sources of error. Of the many researches which they instituted to determine this point, none was more apparently conclusive than that of the well-known willow tree experiment of Van Helmont, which long deceived, from its apparent accuracy, the philosophers of that age. This celebrated experimentalist planted a willow which weighed 5 lbs. in a common earthen vessel filled with 200 lbs. of soil, which had been previously thoroughly dried in an oven, and then moistened with only rain-water. This earthen vessel he placed in the earth in a garden, covering it over in such a manner that all access of dust, &c., was prevented. For five years this willow continued to grow, although moistened only with either rain or distilled water. At the end of that period, it was found to weigh 1694 lbs., although the earth in which it was planted, when again dried and weighed, was found to have lost only two ounces of its original weight. Here, then, said the contemporaries of Van Helmont, is an increase of 164 lbs., and yet the only food the willow had was water; it is evident, therefore, that pure water, and water only, is quite sufficient to support vegetation. Various sources of error were, however WATER. A well-known, universally dif fused substance, which in ordinary tempera-speedily discerned to prove that this experitures is fluid, but is solid when cooled down to 32° of Fahrenheit's thermometer. It rises into vapour at all temperatures, even below the freezing point, and at 212° expands suddenly into steam. It is composed, by weight, of oxy-contained sufficient earthy matters to supply gen 8 parts, and hydrogen 1 part. Water is one of the most useful elements in the arts and manufactures, as well as in rural and domestic economy. The extensive utility of water for imparting motion to machinery, and for domestic purposes, is too well known to require explanation; and as we have already treated of its beneficial properties for irrigating land, under this head we shall have principally to confine ourselves to its uses to plants. Its Uses to Vegetation. The value of water to vegetation very early attracted the attention of mankind. In the most ancient of all books, Genesis ii. 10, we are told that "a river went out of Eden to water the garden." And the earliest of the Greek and Egyptian philosophers, astonished and confused by the magic effects which water produced upon the rank and luxuriant lands of the warm eastern climates, were loud in their praises of the unaided powers of water to support vegetation. They not only regarded it as one of the four elements of which the world was composed, but Hippocrates considered it to be the substance which nourishes and supports plants and animals. Theophrastus even considered that all metals were produced from water. The opinion that pure water, and water only, was able to support vegetation, was in succeeding ages long the opinion of many philosophers distinguished for their laborious investigations and their ardent love of truth. Amongst these may be named Van Helmont, Bonnet, Duhamel, Tillet, and the illustrious Boyle. These great men deceived themselves, however, by not sufficiently attending to the purity of the water ment was totally insufficient to decide this question. The illustrious Bergman, in 1773, showed that the rain-water employed by Van Helmont, so far from being chemically pure, the whole of that found in the willow tree. And, in addition to this, it was afterwards shown that unglazed earthen vessels readily imbibe and transmit the moisture of the soil in which they are placed: now this moisture abounds with a variety of solid matters, both organic, earthy, and saline. (Thomson, vol. iv. p. 313.) Still more accurate experiments have been since instituted with water chemically pure, with very different results. In this way all attempts to raise plants have in every instance totally failed, although, as I have in another place had occasion to remark, I have fruitlessly varied the attempt in several ways. See LIQUID MANURE. Although, however, it is, from the result of these laborious researches, pretty clearly proved that water is not the sole food of plants, yet it must be evident to the most casual observer what an indispensable food this universal fluid is to vegetation. To all vegetation, in fact, it is an indispensable necessary of life, although almost every species of plant requires to be supplied with it in varying proportions: some, such as the aërial epidendron, and other Oriental plants, being able to supply themselves from merely the aqueous portion of it which always exists in the atmosphere; while some, such as the rice plant, and the aquatics, cannot prosper without being supplied with it in such copious quantities as would be destructive to the ordinary crops of the farmer. In some proportion or other, however, they all require it, and all attempts have been in vain made to cause plants to grow in situations where moisture was absolutely removed both from the earth and their surrounding atmosphere. in all ordinary temperatures. This unvaried presence of aqueous vapour in the atmoM. Berthollet was of opinion that the leaves sphere is not less remarkable by the immense of plants have the power of decomposing wa- importance it is to vegetation; for without the ter when exposed to the light of the sun. The assistance which the farmer's crops derive oxygen gas, according to this distinguished from it in dry weather, the warmth of the sun philosopher, which is always emitted under would too often in the summer months wither these circumstances, is derived partly from the and destroy them. This beautiful arrangedecomposition of the water. "Indeed,” adds ment of creative wisdom did not escape the Dr. Thomson, "If we consider the great quan- attention of Davy, who noted too the variations tity of hydrogen contained in plants, it is diffi- in its quantity according to the changing decult to conceive how they should obtain it, mands of vegetation. The quantity of water, provided the water they absorb does not con- he remarked (Elements of Agr. Chem. p. 207), tribute to furnish it." (System of Chem. vol. iv. which exists in air as vapour, varies with the p. 349.) These views open a field for future temperature. In proportion as the weather is and highly interesting researches, which will hotter the quantity is greater. At 50° of Fahprobably lead to the establishing of new facts renheit's thermometer, air contains about onehighly important to the cultivator. And as fiftieth of its volume of vapour; and as the Davy, the chief of chemists, well said, "We specific gravity of vapour is to that of air nearly can only reason from facts. We cannot imi- as 10 to 15, this is about one seventy-fifth of its tate the powers of composition belonging to weight. At 100°, supposing that it has a free vegetable structures, but at least we can under- communication with water, it contains about stand them; and as far as our researches have one-fourteenth part in volume, or one twentygone, it appears that in vegetation compound first in weight. It is the condensation of va forms are uniformly produced from simpler pour by the diminution in the temperature of ones; and the elements in the soil, the atmo- the atmosphere which is probably the princisphere, and the earth, absorbed and made parts | pal cause of the formation of clouds, and of of beautiful and diversified structures." (Lec- the deposition of dew, mist, snow, or hail. The tures, p. 314.) Pure water, therefore, is certainly not capable of entirely supporting vegetation. Yet, although it cannot produce effects so extensive as these, yet its uses are many and important, and it is more than probable that it is decomposed by plants, its oxygen partially evolved, and its hydrogen assimilated with carbon and oxygen into a variety of vegetable substances, most of which contain hydrogen in some form or other: thus Sugar is composed of Starch; of Hydrogen Oxygen Parts. 49.38 100 6-43 51.46 42.11 100 6.22 49-78 44. 100 leaves of living plants appear to act upon the vapour likewise in its elastic form, and to absorb it. Some vegetables increase in weight from this cause when suspended in the atmosphere, and unconnected with the soil; such are the house-leek, and different species of the aloe. In very intense heats, adds Davy, and when the soil is dry, the life of plants seems to be preserved by the absorbent power of their leaves; and it is a beautiful circumstance in the economy of nature, that aqueous vapour is most abundant in the atmosphere when it is most needed for the purposes of life, and that when other sources of its supply are cut off, this is most copious. And, again, when water is combined with saline substances, the roots of plants separate it from them in a very remarkable manner. Some curious experiments of this kind were made by M. Saussure. See SALTS, their Uses to Vegetation. That plants have the power, when nourished only with pure water, of decomposing the carbonic acid gas of the atmosphere, has been shown by some very careful experiments of M. Saussure. He found that some sprigs of peppermint, when supplied with pure water only, and allowed to vegetate for some time in the light, nearly doubled the portion of carbon It would be difficult indeed to account for the which they originally contained. The quanlarge proportion of hydrogen present in vege-tity of water which, under ordinary circumtable substances, without we allow that in some instances water is decomposed by the plant. "All the hydrogen," says Professor Liebig, rather too sweepingly, "necessary for the formation of an organic compound is supplied to a plant by the decomposition of water. (Organ. Chem. p. 66.) That plants have a strong attraction for water is evident from variety of circumstances; thus by their leaves and roots they separate the aqueous vapour of the atmosphere from the gases in which it is contained, and that too stances, plants absorb, is very considerable; thus, Dr. Hales ascertained that a cabbage transmits into the atmosphere, by insensible vapour, about half its weight of water daily; and that a sunflower, feet in height, transpired in the same period nearly 2 lbs. weight. (Veg. Statics, vol. i. p. 5, 15.) Dr. Woodward found that a sprig of mint, weighing 27 grains, in 77 days emitted 2543 grains of water. A sprig of spearmint, weighing 27 grains, emitted in the same time 2558 grains. A sprig of common nightshade, weighing 49 grains, evolved 3708 grains, and a lathyrus of 98 grains | meadows of the south of England and of Scotemitted 2501 grains. In a previous page of this Encyclopædia, I have endeavoured to show the various uses of the earths to vegetation. (See EARTHS.) The cultivator will observe how many of their chief fertile properties are connected with their attraction for the aqueous vapour of the atmosphere, their powers of absorption, their capability of retaining it. It is in vain, indeed, by any contrivance to attempt to make plants of any description vegetate in absolutely dry earth, or in air from which the aqueous vapour is entirely withdrawn. It is true that some of the flowering roots of the East, and some of the mosses of our own country, almost appear to do so; but such plants support themselves by absorbing a certain degree of moisture, even when suspended, as in oriental countries, by a silken cord from the ceiling of the room, or from apparently dry brick walls; for when by chemical means the moisture is entirely removed from them, even these hardy plants cease to vegetate. land are formed on subsoils of broken flints, gravels, and the roughest shingle. And, again, the meadow-lands often need such copious supplies of moisture as would be the means of destroying the grain crops. The surface water which tenants many uncultivated soils is generally surcharged with a variety of foreign substances, very commonly with vegetable matters. That in the gravelly soils is usually surcharged with oxide of iron; that resting on calcareous soils, with sulphate of lime (gypsum); whilst those from peat lands commonly abound with sulphate of iron, or the red oxide of the same metal. ence is extended to the most upland soils. It removes the land springs, and dries the surface of thousands of acres of even the most elevated of the English gravels. In most of the soils which the farmer has to bring into cultivation, the removal of these waters is his first care; for such an abundance of moisture is not only pernicious, from the usual bad quality of the land water, but from the quantity being far too great for the habits of the plants which the farmer intends to cultivate; such waters, too, dissolve, and sometimes carry off from the soil, in their imperVarious foreign substances have been sup- ceptible drainage, all the soluble richest porposed to exist in minute proportions in rain- tion of the soil. For many reasons, therefore, water, to which its fertilizing effects have been draining has been long very justly held to be chiefly ascribed: thus ammonia is believed by the foundation of all agricultural improveProfessor Liebig to exist in rain-water. No-ments; since its good effects are not confined thing, however, is more likely to lead to erro-to the low marsh land, but its beneficial influneous general conclusions than the detection of minute foreign substances in water. Such hasty generalizations have often deceived the most excellent philosophers: thus the great Boyle, by digesting pure water for a lengthened period in glass vessels hermetically sealed, found that it deposited a minute quantity of flint in powder; and hence he was led to conclude that water was in this way converted by long boiling into silica, an error which several other philosophers adopted, until the celebrated Lavoisier and Dr. Priestley proved that the flint deposited arose from the water having, by long boiling, partially dissolved the glass. In the same way even Davy, the most cautious of experimentalists, once thought that chlorine and soda might, by the influence of the voltaic pile, be obtained from water absolutely pure; but more careful and rigid experiments soon convinced him of the extreme difficulty of procuring entirely pure water, the vessels in which the water was procured communicating, with every apparent caution, sundry impurities; and this difficulty, I think it very likely, the skilful chemists of Germany have not successfully escaped. Almost to an equally beneficial extent has the addition of water to plants for a lengthened period been carried on by the cultivator in a variety of modes; by the gardener, either ir. steam in his conservatories, or by the watering pot in the open ground. Almost endless, in deed, are the varieties of artificial irrigation, from the minor applications of the gardener to the more gigantic efforts of the managers of the water-meads. It is this branch of the investigation of the uses of water to vegetation which is the most interesting to the farmer, and to the head IRRIGATION I must refer the reader. In regarding the uses of water to vegetation in this manner, however, the cultivator must remember that it is not pure water that he is thus using for his crops, but, as I have be fore remarked, water surcharged with a variety of earthy, saline, and organic matters, to whose presence a chief portion of the fertilizing effect of such streams must be attributed; for it is found that the most foul and impure waters are Water exists in all cultivated land in some much the best for the purposes of irrigation: proportion or other. The quantity, however, thus the water of a river below a town is found necessary to be present in the farmer's soils to to be much more fertilizing than the same waobtain the maximum advantage varies with ter before it has been mixed with the contents their nature, the climate, and the crop. For of the sewers. These are facts well known, instance, the rice-fields of India require a de- for instance, to the owners of the fine water gree of moisture which would be utterly de- meadows of the valleys of the Itchen, the Kenstructive to the grain crops of the English far- net, and the Avon. That of the Thames above mer. The most porous, sandy land in a rainy the influence of the tide is not nearly so valua climate will be prolific, when the same soil in ble to the grazier as it is after it has had mixed a dry, warm country will be absolutely barren. with its waters the huge mass of impure matters Even the drifting sands of Arabia, for instance, from the London sewers. Then, again, by far if placed under the incessant rains of the Ame- the richest irrigating waters, because the very rican Andes, would certainly be speedily cover- foulest of all, are those of the sewers of the ed with vegetation. Some of the richest water-city of Edinburgh, which produce such singu larly luxuriant crops of grass on the Craigintinny meadows. This observation is not confined to the English graziers: those of the duchy of Milan long since made the same remark. Half a century since, Mr. Songa, when describing the meads of the banks of the Brembo, says, "That water is found excellent which passes through the fosses of the town of Treviglio, and discharges itself from them by forming a canal of 8 or 10 feet broad, and 1 foot or 1 foot deep. The lands irrigated with this water seem to receive every time the advantage of a dunging, and on this account sell from a third to a half dearer than any other of an equal quality of soil." (Young's Annals, 1793, p. 182.) Watering the land to add to its fertility is a very ancient practice. Such, then, are a few of the well-ascertained facts with regard to the application of water to vegetation, uses which are so valuable when well understood by the farmer. In all his operations this universal fluid will be found to influence his arrangements; and in a due and regular supply of it to his crops consists, in fact, the success of most of his efforts. If, for instance, a farmer would judge of the value of a particular field from merely a specimen of its soil, the attraction of the previously dried earth for the moisture of the atmosphere will afford a very tolerable indication of its comparative value; those soils which attract the most water being commonly those which obtain the highest rents. All researches like these, in many obvious and indirect ways, are attended with considerable advantage to the cultivator. For, the more he becomes acquainted with the uses and properties of water, the more readily will he be able to avail himself of every opportunity which may present itself for extending its sphere of usefulness. It is idle to conclude that every thing possible has been effected with regard to the agricultural uses of water; for, saying nothing of the inferior extent of our water meads to those of even the banks of the Italian rivers, much still remains to be accomplished in rendering available, not only the liquid drainage of our large towns, but in the use of the steam-engine for the purposes of irrigation; an agent to which I have in this work already alluded, and for obtaining whose magic assistance the farmers of no other country are so well situated as those of our own island. To the cultivator, therefore, an examination of the powers and properties of water will in many ways be attended with benefit; for if the farmer once seriously contemplates the powerfully invigorating and enriching qualities of the waters near to which he is very often placed, the abundance of organic matters which they contain, and the advantages to be derived from their judicious application, he will speedily devise some means or other by which he may avail himself of this too often neglected agent. The finely divided earthy and organic matters which now so copiously pollute the waters of our rivers are in fact the only great drawbacks upon the otherwise gradually increasing productiveness of the land. (See ALLUVIUM and WARPING.) These, be it remembered, are ever quietly yet incessantly acting as drains upon the fertility of the land; they never cease the work of impoveristiment; and it is only by the efforts of the merchant, the fisherman, and the irrigator, that any portion of these finely divided matters ever return again to the cultivated soils of our country. See IRRIGATION and RAIN. WATER-ALOE, or WATER SOLDIER (Stratiotes aloides; from stratos, an army, in allusion to its long sword-like leaves). In England, an ornamental native aquatic, which fills the ditches in summer with a close phalanx of sword-like leaves, and increases so fast in the ponds where it is planted as to become almost a troublesome weed. In its wild state it inhabits deep ditches and pools, and is a stoloniferous, smooth, floating herb, with numerous radical leaves, and a solitary central flower-stalk, but no stem. The parent plant sinks to the bottom after flowering, and sends out long simple runners, each terminating in a leaf, bud, or young plant, which first takes root in the mud, by several long fibres, and in the following summer rises to the surface of the water, blossoms and then again subsides to ripen its seeds and throw out fresh runners, each tuft of leaves flowering but once. The leaves are a span long or more, acute, highly vascular, fringed with very sharp saw-like teeth. Flowers white, large and handsome, the stalk firm, stout, two-edged, much shorter than the leaves. WATER-CARPET. A name in Pennsylvania for the GOLDEN SAXIFRAGE, which see. WATER-COWBANE. See CowBANE. WATER-CRESS. See CRESS. WATER-DROPWORT. See DROPWORT. WATER-ELDER. See GUELDER ROSE. WATER-FARCY. See FARCY. WATER-HEMLOCK. See CowBANE. WATER-LILY, THE FRINGED. BUCK BEAN. See WATER-LILY, YELLOW.-See LILY, WA TER. WATER-LILY, WHITE. See LILY, WATER. WATER-MELON. The following directions for cultivating water-melons for an early market, are given in the Southern Agriculturist. Select a high and dry soil for the purpose. Plough it up well, and harrow it. Check off the spot thus treated at distances of 10 feet each way. Dig out each check with a hoe or spade, and into the same place 5 or 6 quarts of cotton seed; or if this cannot be procured, fill the place with stable manure, partly decomposed. Haul over this the earth before dug from the hole, and mix it well with the manure. If you have used cotton seed, in the spring, it will have sprouted a week or two after being put into the hole; and must now be killed by chopping up the same well, and mixing it with the soil. This being done, you may now haul up the manure and earth as before directed, into hills, on the top of which you must place about a peck of sand, taken from some street or well-travelled road. Your hills will be now ready for planting. I should, however, state that the hills must, instead of being made high, be made flat and broad. Soak your seed over night in milk-warm water, and plant them out the next mming, placing from 5 to 6 seed to each hill. The |