a well known fluid, diffused through the atmosphere, and over the surface of the globe, and abounding in a certain proportion in animals, vegetables, and minerals.
The uses of water are so universally known, that it would be superfluous to enumerate them in this article. It is essential to animal and vegetable life; it makes easy the intercourse between the most distant regions of the world; and it is one of the most useful powers in the mechanic arts. It is often found combined with various substances, and is then frequently beneficial in curing or alleviating diseases.
Those properties of water which fit it for answering mechanical purposes are explained in other articles of this work (see Hydrodynamics, Pneumatics, No. 3. Resistance, and Rivers); and for the discovery of the composition of water, see Chemistry Index.
Mineral Waters. For the method of analysing them, see also Chemistry Index.
Under the title of Mineral Waters, we have given an analysis of the most remarkable waters in Europe.
Holy Water, which is made use of in the church of Rome, as also by the Greeks, and by the other Christians of the East of all denominations, is water with a mixture of salt, blessed by a priest according to a set form of benediction. It is used in the blessing of persons, things, and places; and is likewise considered as a ceremony to excite pious thoughts in the minds of the faithful.
The priests, in blessing it, first, in the name of God, commands the devils not to hurt the persons who shall be sprinkled with it, nor to abuse the things, nor disturb the places, which shall likewise be so sprinkled. He then prays that health, safety, and the favour of heaven, may be enjoyed by such persons, and by those who shall use such things, or dwell in such places. Vessels, vefells, and other such things that are set apart for divine service, are sprinkled with it. It is sometimes sprinkled on cattle, with an intention to free or preserve them from diabolical enchantments; and in some ritual books there are prayers to be said on such occasions, by which the safety of such animals, as being a temporal blessing to the possessors, is begged of God, whose providential care is extended to all his creatures. The hope which Catholics entertain of obtaining such good effects from the devout use of holy water, is grounded on the promise made to believers by Christ (St Mark xvi. 17.), and on the general efficacy of the prayers of the church; the petition of which prayers God is often pleased to grant; though sometimes, in his Providence, he sees it not expedient to do so. That such effects have been produced by holy water in a remarkable manner, has been asserted by many authors of no small weight; as, namely, by St Epiphanius, Haer. 30th; St Hierom, in the Life of St Hilarion; Theodoret Hist. Eccl. lib. v. cap. 21.; Palladius, Hist. Lauf.; Bede, lib. v. cap. 4.
As a ceremony (says the Catholic), water brings to our remembrance our baptism; in which, by water, we were cleansed from original sin. It also puts us in mind of that purity of conscience which we ought to endeavour always to have, but especially when we are going to worship our God. The salt, which is put into the water to preserve it from corrupting, is also a figure of divine grace, which preserves our souls from the corruption of sin; and is likewise an emblem of that wisdom and discretion which ought to season every action that a Christian does, and every word that he says. It is wont to be blessed and sprinkled in churches on Sundays, in the beginning of the solemn office. It is kept in vessels at the doors of the same churches, that it may be taken by the faithful as they enter in. It is also often kept in private houses and chambers.
Putrid Water, is that which has acquired an offensive smell and taste by the putrefaction of animal or vegetable substances contained in it. It is in the highest degree pernicious to the human frame, and capable of bringing on mortal diseases even by its smell. It is not always from the apparent muddiness of waters that we can can judge of their disposition to putrefy; some which are seemingly very pure, being more apt to become putrid than others which appear much more mixed with heterogeneous matters. Under the article ANIMALCULE, No. 33, is mentioned a species of insects which have the property of making water stink to an incredible degree, though their bulk in proportion to the fluid which surrounds them is less than that of one to a million. Other substances no doubt there are which have the same property; and hence almost all water which is confined from the air is apt to become offensive, even though kept in glass or stoneware vessels. Indeed it is a common observation, that water keeps much longer sweet in glass vessels, or in those of earthen or stoneware, than in those of wood, where it is exceedingly apt to putrefy. Hence, as ships can only be supplied with water kept in wooden casks, sailors are extremely liable to those diseases which arise from putrid water; and the discovery of a method by which water could easily be prevented from becoming putrid at sea would be exceedingly valuable. This may indeed be done by quicklime; for when water is impregnated with it, all putrefactive matters are either totally destroyed, or altered in such a manner as never to be capable of undergoing the putrefactive fermentation again. But a continued use of lime-water could not fail of being pernicious, and it is therefore necessary to throw down the lime; after which the water will have all the purity necessary for preserving it free from putrefaction. This can only be done by means of fixed air; and mere exposure in broad shallow vessels to the atmosphere would do it without anything else, only taking care to break the crust which formed upon it. Two methods, however, have been thought of for doing this with more expedition. The one, invented by Dr Alston, is, by throwing into the water impregnated with lime a quantity of magnesia. The lime attracts fixed air more powerfully than magnesia; in consequence of which the latter parts with it to the lime: and thus becoming insoluble, falls along with the caustic magnesia to the bottom, and thus leaves the water perfectly pure. Another method is that of Mr Henry, who proposes to throw down the lime by means of an effervescing mixture of oil of vitriol and chalk put down to the bottom of the water cask. His apparatus for this purpose is as simple as it can well be made, though it is hardly probable that sailors will give themselves the trouble of using it; and Dr Alston's scheme would seem better calculated for them, were it not for the expense of the magnesia; which indeed is the only objection made to it by Mr Henry. Putrid water may be restored and made potable by a process of the same kind.
Of late it has been discovered that charcoal possesses many unexpected properties, and, among others, that of preferring water from corruption, and of purifying it after it has been corrupted. Mr Lowitz, whose experiments on charcoal have been published in Crell's Chemical Journal, has turned his attention to this subject in a memoir read to the Economical Society at Peterburgh. He found that the effect of charcoal was rendered much more speedy by using along with it some sulphuric acid. One ounce and a half of charcoal in powder, and 24 drops of concentrated sulphuric acid (oil of vitriol), are sufficient to purify three pints and a half of corrupted water, and do not communicate to it any sensible acidity. This small quantity of acid renders it unnecessary to use more than a third part of the charcoal powder which would otherwise be wanted; and the lees of that powder is employed, the lees is the quantity of water left by the operation, which, in sea-voyages, is an object worthy of consideration. In proportion to the quantity of acid made use of, the quantity of charcoal may be diminished or augmented. All acids produce nearly the same effects: neutral salts also, particularly nitre and soda-falt, may be used, but sulphuric acid is preferable to any of these; water which is purified by means of this acid and charcoal will keep a longer time than that which is purified by charcoal alone. When we mean to purify any given quantity of corrupted water, we should begin by adding to it as much powder of charcoal as is necessary to deprive it entirely of its bad smell. To ascertain whether that quantity of powdered charcoal was sufficient to effect the clarification of the said water, a small quantity of it may be passed through a linen bag, two or three inches long; if the water, thus filtrated, still has a turbid appearance, a fresh quantity of powdered charcoal must be added, till it is become perfectly clear: the whole of the water may then be passed through a filtering bag, the size of which should be proportioned to the quantity of water. If sulphuric acid, or any other, can be procured, a small quantity of it should be added to the water, before the charcoal powder.
The cleaning of the casks in which water is to be kept in sea-voyages should never be neglected: they should be well washed with hot water and sand, or with any other substance capable of removing the mucilaginous particles, and afterwards a quantity of charcoal dust should be employed, which will entirely deprive them of the musty or putrid smell they may have contracted.—The charcoal used for purifying water should be well burnt, and afterwards beat into a fine powder.
Sea-WATER. See SEA-Water.
Water-Carts, carriages constructed for the purpose of watering the roads for several miles round London; a precaution absolutely necessary near the metropolis, where, from such a vast daily influx of carriages and horses, the dust would otherwise become quite insufferable in hot dry weather. Pumps are placed at proper distances to supply these carts.
Water-Ordeal. See ORDEAL.
Water, among jewellers, is properly the colour or lustre of diamonds and pearls. The term, though less properly, is sometimes used for the hue or colour of other stones.
Water-Bellows. See Machines for blowing Air into FURNACES.
Water-Colours, in Painting, are such colours as are only diluted and mixed up with gum-water, in contradistinction to oil-colours. See COLOUR-Making.
Water-Gang, a channel cut to drain a place by carrying off a stream of water.
Water-Hen. See Parra, Ornithology Index.
Water-Lines of a Ship, certain horizontal lines supposed to be drawn about the outside of a ship's bottom, close to the surface of the water in which she floats. They are accordingly higher or lower upon the bottom, in proportion to the depth of the column of water required to float her.
Water-Logged, the state of a ship when, by receiving a great quantity of water into the hold, by leaking, &c. she has become heavy and inactive upon the sea, so as to yield without resistance to the efforts of every wave rushing over her decks. As, in this dangerous situation, the centre of gravity is no longer fixed, but fluctuating from place to place, the stability of the ship is utterly lost: she is therefore almost totally deprived of the use of her sails, which would operate to overset her, or press the head under water. Hence there is no resource for the crew, except to free her by the pumps, or to abandon her by the boats as soon as possible.
WATER-Sail, a small sail spread occasionally under the lower studding-sail, or driver boom, in a fair wind and smooth sea.
WATER-Oxel. See TURDUS, ORNITHOLOGY Index.
WATER-Spout, an extraordinary meteor, consisting of a large mass of water collected into a sort of column, and moved with rapidity along the surface of the sea.
The best account of the water-spout which we have met with is in the Phil. Transf. Abridged, vol. iii. as observed by Mr Joseph Harris, May 21, 1732, about sunset, lat. 32° 50' N.; long. 9° E. from Cape Florida.
"When first we saw the spout (ays he), it was whole and entire, and much of the shape and proportion of a speaking trumpet; the small end being downwards, and reaching to the sea, and the big end terminated in a black thick cloud. The spout itself was very black, and the more so the higher up. It seemed to be exactly perpendicular to the horizon, and its sides perfectly smooth, without the least ruggedness. Where it fell the spray of the sea rose to a considerable height, which made somewhat the appearance of a great smoke. From the first time we saw it, it continued whole about a minute, and till it was quite dissipated about three minutes. It began to waste from below, and so gradually up, while the upper part remained entire, without any visible alteration, till at last it ended in the black cloud above; upon which there seemed to fall a very heavy rain in that neighbourhood.—There was but little wind, and the sky elsewhere was pretty serene."
Water-spouts have by some been supposed to be merely electrical in their origin; particularly by Signior Beccaria, who supported his opinion by some experiments. But if we attend to the successive phenomena necessary to constitute a complete water-spout through their various stages, we shall be convinced, that recourse must be had to some other principle in order to obtain a complete solution.
Dr Franklin, in his Physical and Meteorological Observations, supposes a water-spout and a whirlwind to proceed from the same cause; their only difference being, that the latter passes over the land, and the former over the water. This opinion is corroborated by M. de la Prome, in the Philosophical Transactions, where he describes two spouts observed at different times in Yorkshire, whose appearances in the air were exactly like those of the spouts at sea, and their effects the same as those of real whirlwinds.
A fluid moving from all points horizontally towards a centre, must at that centre either mount or descend. If a hole be opened in the middle of the bottom of a tub filled with water, the water will flow from all sides to the centre, and there descend in a whirl: but air flowing on or near the surface of land or water, from all sides towards a centre, must at that centre ascend; because the land or water will hinder its descent.
Vol. XX. Part II.
The doctor, in proceeding to explain his conceptions, begs to be allowed two or three positions, as a foundation for his hypothesis. 1. That the lower region of air is often more heated, and so more rarefied, than the upper, and by consequence specifically lighter. The coldness of the upper region is manifested by the hail, which falls from it in warm weather. 2. That heated air may be very moist, and yet the moisture so equally diffused and rarefied as not to be visible till colder air mixes with it; at which time it condenses and becomes visible. Thus our breath, although invisible in summer, becomes visible in winter.
These circumstances being granted, he supposes a tract of land or sea, of about 60 miles in extent, unsheltered by clouds and unrefreshed by the wind, during a summer's day, or perhaps for several days without intermission, till it becomes violently heated, together with the lower region of the air in contact with it; so that the latter becomes specifically lighter than the superincumbent higher region of the atmosphere, wherein the clouds are usually floated: he supposes also that the air surrounding this tract has not been so much heated during those days, and therefore remains heavier. The consequence of this, he conceives, should be, that the heated lighter air should ascend, and the heavier descend; and as this rising cannot operate throughout the whole tract at once, because that would leave too extensive a vacuum, the rising will begin precisely in that column which happens to be lightest or most rarefied; and the warm air will flow horizontally from all parts of this column, where the several currents meeting, and joining to rise, a whirl is naturally formed, in the same manner as a whirl is formed in a tub of water, by the descending fluid receding from all sides of the tub towards the hole in the centre.
And as the several currents arrive at this central rising column with a considerable degree of horizontal motion, they cannot suddenly change it to a vertical motion: therefore as they gradually, in approaching the whirl, decline from right to curve or circular lines, so, having joined the whirl, they ascend by a spiral motion; in the same manner as the water descends spirally through the hole in the tub before mentioned.
Lastly, as the lower air nearest the surface is more rarefied by the heat of the sun, it is more impressed by the current of the surrounding cold and heavy air which is to assume its place, and consequently its motion towards the whirl is swifter, and so the force of the lower part of the whirl strongest, and the centrifugal force of its particles greatest. Hence the vacuum which incloes the axis of the whirl should be greatest near the earth or sea, and diminish gradually as it approaches the region of the clouds, till it ends in a point.
This circle is of various diameters, sometimes very large.
If the vacuum passes over water, the water may rise in a body or column therein to the height of about 32 feet. The whirl of air may be as invisible as the air itself, though reaching in reality from the water to the region of cool air, in which our low summer thunderclouds commonly float; but it will soon become visible at its extremities. The agitation of the water under the whirling of the circle, and the swelling and rising of the water in the commencement of the vacuum, render it visible below. It is perceived above by the warm air being brought up to the cooler region, where its moisture begins to be condensed by the cold into thick vapour, and is then first discovered at the highest part, which being now cooled condenses what rises behind it, and this latter acts in the same manner on the succeeding body; where, by the contact of the vapours, the cold operates faster in a right line downwards, than the vapours themselves can climb in a spiral line upwards: they climb however; and as by continual addition they grow denser, and by consequence increase their centrifugal force, and being riven above the concentrating currents that compose the whirl, they fly off, and form a cloud.
It seems easy to conceive, how, by this successive condensation from above, the spout appears to drop or descend from the cloud, although the materials of which it is composed are all the while ascending. The condensation of the moisture contained in so great a quantity of warm air as may be supposed to rise in a short time in this prodigiously rapid whirl, is perhaps sufficient to form a great extent of cloud; and the friction of the whirling air on the sides of the column may detach great quantities of its water, disperse them into drops, and carry them up in the spiral whirl mixed with the air. The heavier drops may indeed fly off, and fall in to a shower about the spout; but much of it will be broken into vapour, and yet remain visible.
As the whirl weakens, the tube may apparently separate in the middle; the column of water subsiding, the superior condensed part drawing up to the cloud. The tube or whirl of air may nevertheless remain entire, the middle only becoming invisible, as not containing any visible matter.
Dr Lindfay, however, in several letters published in the Gentleman's Magazine, has controverted this theory of Dr Franklin, and endeavoured to prove that water-spouts and whirlwinds are distinct phenomena; and that the water which forms the water-spout, does not ascend from the sea, as Dr Franklin supposes, but descends from the atmosphere. Our limits do not permit us to insert his arguments here, but they may be seen in the Gentleman's Magazine, volume li. p. 559, 615; vol. llii. p. 1025; and vol. lv. p. 594. We cannot avoid observing, however, that he treats Dr Franklin with a degree of asperity to which he is by no means entitled, and that his arguments, even if conclusive, prove nothing more than that some water-spouts certainly descend; which Dr Franklin hardly ever ventured to deny. There are some very valuable dissertations on this subject by Professor Wilce of Upsal.