of the modern inventions of science, the steamengine. At present we can only offer a familiar elucidation or two of the amazing increase of volume, and rapid condensation of steam in this way. Take a Florence flask with water in the bottom, boil it over a spirit lamp; and afterwards invert about two inches and a half of the neck in a vessel of cold water. The water will rise with a gush upwards into the flask, filling the vacuum; (and therefore nearly the flask), made by the steam having been condensed.

However long we boil water in an open vessel, it may be observed, we cannot make it in the smallest degree hotter than its boiling point: then the vapor absorbs the heat, and carries it off as fast as it is generated. Yet by continued heat, united with additional compression, both the expansibility and temperature of steam may be greatly increased and some constructors of steam-engines have availed themselves of this property, to augment the power and diminish the expense of them. These are what are called high pressure engines.

But a singular difference has been lately noticed by M. Gay Lussac, with regard to the vessel in which water is boiled. He has ascertained that water boiling in a glass vessel has a temperature of 214-2°, and in a tin vessel contiguous to it of only 212°. A few particles of pounded glass, thrown into the former vessel, reduced the thermometer plunged in it to 212-6°, and iron filings to 212°. When the flame is withdrawn for a few seconds, from under a glass vessel of boiling water, the ebullition will recommence on throwing in a pinch of iron filings. Of what future importance this may be to chemistry, or the arts, we do not presume to judge: but only mention it as a singular and very modern observation (considering for how many centuries water has been boiled) on the peculiarities of that body.

To return from this incidental notice of steam, and the steam-engine, we may suggest a few chemical tests of the purity of water.

1. Iron very commonly impregnates it: this is the case whenever it flows through a gravelly soil. The presence of iron may be detected by pouring into water prussiate of potash, when a blue precipitate is the result: the Prussian blue of commerce. 2. The gallic acid, very astringent, or any vegetable astringents of that kind in water may be detected by pouring into it sulphate of iron, when a black inky precipitate results. This is not frequently seen in settled, but in unsettled or uncleared countries, like the western part of the United States, it is found through the falling of the leaves and bark of trees into standing waters.

3. The presence of lime in water is detected by breathing into it: the lungs decompose the atmospheric air, and, yielding carbonic acid, produce a carbonate of lime.

4. Passing now into that useful laboratory, the kitchen, copper, one of the most deadly poisons, is but too often carelessly in use there: its presence is to be detected by plunging a common iron knife into water. Copper is formed on the knife, arising from the greater affinity of iron for oxygen, the iron having decomposed the salt of copper in the water.

5. Do we suspect sulphuric acid to be present? It may be detected by pouring in the suspected water a vegetable infusion. Pour the tested body on the test, and the vegetable blue becomes a red.

6. Volatile alkali? This is detected in a simiar manner. Only the vegetable infusion now be comes green.

As an

The different temperature at which water boils, as compared with all spirituous liquids, is the foundation of the art of DISTILLATION, which see. In the largest application of the principles of that art in this country, i. e. to the distillation of gin, malt-wash is boiled from 190° to 195° Fahrenheit, (water not boiling until it arrives at 212°, as we have seen); when the spirit separates from the water, and comes over in the form of steam, which is condensed in passing through the long pipes of the worm surrounded with cold water. evening amusement we may attempt the French manufacture of brandy, without fear of a visit from the officers of excise: in fact distil it from port wine, over the spirit lamp: boiled in the retort, the steam will gradually come over and be condensed in the reservoir. 2. Ether may in a similar manner be boiled in water, but just warm. It boils at 98° in the air: in vacuo at 20° Fahrenheit. 3. Spirit-bombs show the expansive force of the steam of spirit, which like that of water is ungovernable at a certain point. Hence the explosion of steam-engines.

Another familiar elucidation of the qualities of water may close this part of our subject. Viewing it generally in connexion with a yielding medium, we may imagine its particles have no actual hardness; and therefore cannot be subject to the laws of friction.

But taken distilled in an exhausted tube; composing what is called a water-mallet; and the sound produced by the streams striking on the bottom of the tube, proves that there is a point at which its particles do not yield.

The chemistry of water is very simple; it is comparatively of late discovery; yet nothing in the whole compass of experimental science appears, in its principal points, to be better established.

Philosophy recognised water as an element, one of the four elements,' from the times of Aristotle to those of the late Mr. Cavendish. That gentleman demonstrated, about the year 1784, that it is composed, in fact, of two distinct aëriform fluids-oxygen and hydrogen; containing eightyeight parts by weight out of every 100 of the former and twelve of the latter. This was the result of three years of laborious experiments.

The late Mr. Watt, the celebrated improver of the steam-engine, seems to have inferred at the same period (in 1783), independently of Mr. Cavendish, that water was a compound body of the kind it has been since proved to be; as did the French chemist Lavoisier and La Place. A friend of the latter, count Monge of Paris, seems to have been the first that suggested an experiment which is often exhibited to the present day, as placing the composition of water beyond dispute. He passed the steam of water through a red-hot iron tube, and found that the water was oxidised; that is, the oxygen attached itself to the iron, and the hydrogen disengaged. The hydrogen is, in this experiment, proved not to be steam by being forced through cold water. But what is called the grand experiment of the French chemists, as to the composition of water, occupied more than nine days of the month of May, 1790. The combustion of the gases was kept up by Fourcroy, Vauquelin, and Seguin, on this occasion, 185 hours, during which

the machine was not quitted for a moment; the experimenters alternately refreshing themselves when fatigued by lying down for a few hours on mattresses in the laboratory.

The volume of hydrogen employed was 25963-568 cubic inches, and the weight was 1039-358 grains. The volume of oxygen was 12570-942, and the weight was 6209-869 grains. The total weight of both elastic fluids was 7249-227. The weight of water obtained was 7244 grains, or 12 oz., 4 gros, 45 grains. The weight of water which should have been obtained was 12 oz., 4 gros, 49.227 grains; the deficit being only 4-227 grains-easily accounted for by the imperfection of all human instruments and experiments, especially on such a

scale.

If we take sulphuric or muriatic acid, diluted three parts with water, and pour it upon iron-filings in a glass vessel, the temperature of the mixture will soon be so much increased by the union of the water with the acid, as to enable the iron to decompose a part of the water. A hole being made through a cork which fits the mouth of the phial, and a piece of tobacco-pipe with a very small orifice being fitted into it, and the whole cemented into the phial, the hydrogen gas, as it is separated from the water, will pass in a continued stream through the pipe, and may be set on fire by the flame of a candle. The gas will continue to burn with a blue lambent flame, as long as the decomposition goes on. This shows that the gas is really hydrogen, and that it arises from the decomposition of the water.

That water may be re-formed by the combustion of this gas may be shown by holding a glass bell over the flame of the gas: as the hydrogen burns, it unites with the oxygen of the atmosphere, and the union of the two gases produces water, which will soon be seen to deposit itself like dew on the inside of the glass. These two experiments, taken together, prove the compound nature of water in the most satisfactory manner.

The carburetted hydrogen burnt for lights in the shops and counting houses sometimes, also, will establish the above facts relative to the composition of water. Over the lamps we see bell-glasses with long curved pipes fitted to the top, ending in a small glass vessel. By these pipes what would otherwise become an annoying smoke is consumed, and, uniting with the oxygen of the atmosphere, forms water, which is received in the glass vessel. A friend of ours in Cheapside thus carries off from two burners about half a wine glass full of water every night.

There are other methods of decomposing water. When two wires from the opposite extremities of the galvanic battery are placed in a tube containing water, so that they are distant from each other a quarter of an inch or half an inch, a stream of gas issues from each wire-from the positive wire oxy gen, from the negative hydrogen gas; and these are in the proportions which when exploded, either by galvanism or electricity, re-form water.

Vegetables have the power of decomposing water by an operation peculiar to themselves. If a sun-flower leaf be placed in an inverted jar of water, exposed to the rays of the sun, bubbles of oxygen will be rapidly formed; the leaf having appropriated to itself the hydrogen, and cousequently disengaged the oxygen which forms the bubbles.

Having thus established the great general fact of the composition of water, and what are its component parts, it will be interesting to examine these parts separately.

Oxygen was first obtained by Dr. Priestley in 1774, from the red oxide of mercury exposed to a burning lens; that is, he obtained this gas from the oxide, not knowing or believing it to be a component part of water. He clearly ascertained, however, at this period its two great distinguishing properties of rendering combustion more vivid and eminently supporting life. Scheele, a Danish che-. mist, and Lavoisier, seemed to have obtained it in the same way, without any knowledge of Dr. Priestley's discovery, the same year. It was reserved for Mr. Cavendish, as we have seen, first to suggest, in 1781, and prove beyond dispute in 1784, the important quantum of this vivifying ingredient contained in water. See OXYGEN. We have said its two principal characteristics are promoting combustion and sustaining life. These, perhaps, are in substance one. We all remember the old experiment of the plumbers to ascertain whether they may in safety descend a well; that is, by first letting down a candle-for generally where a candie burns they know a man can breathe.

How eminently this gas supports combustion may be further inferred from the fact that, 1. It relights a taper; 2. Readily produces sulphuric acid from sulphur; 3. Or, with equal readiness, phosphuric acid from phosphorus. We may here add though this eminent supporter of combustion, this gas is not itself a combustible.

Hydrogen, though the much inferior component part of water, has been honored with a name which signifies (vowp, water, and yɛvvaw, to produce) to produce water. See HYDROGEN.

1. In proof of its being the lightest ponderable known, it is the great ingredient used in aerostation. One of Bate's balloons may be sent up in any parlor filled with this gas: it is composed of the maw of a turkey, and filled precisely on the principle of the largest balloons.

2. Hydrogen will not support combustion; if we immerse in it a taper it instantly dies. Yet is this gas highly combustible in atmospheric air: hence its importance in modern times, arising from its extensive use (already adverted to) in lights; and its well known connexion with the explosion> that frequently take place in coal-mines. The investigation of its properties in the latter case has led to Sir Humphry Davy's admirable invention of the SAFETY LAMP, which see. He found that this gas was generated in large quantities, imperceptibly, by the surface of the coal, and then on mixing with the air of the atmosphere went off, on application of a common light, in a violent and dangerous explosion. Sir Humphry Davy's invention simply prevents the light from coming in contact with this dangerous mixture of airs by a gauze veil.

We conclude in the words of a contemporary author, which may suggest a reflection for our younger readers:—

When judgment waked the Almighty hand,
To smite the vile of every land;
Once in six thousand years he hurl'd
A waste of waters on the world.
But through each day of all the years,
Befors and since his hand appears,

of tartar emetic. Its action on oxide of silver is exceedingly violent. Every drop of the liquid let fall on the dry oxide produces a real explosion; and so much heat is evolved, that, if the experiment be made in a dark place, there is a very sensible disengagement of light. Besides the oxide of silver, there are several other oxides, which act with violence on oxygenated water; for example, the peroxide of manganese, that of cobalt, the oxides of lead, platinum, gold, iridium, rhodium, palladium. Several metals in a state of extreme division occasion the same phenomenon; such as silver, platinum, gold, osmium, iridium, rhodium, palladium. In all the preceding cases, it is always the oxygen united to the water which is disengaged, and sometimes likewise that of the oxide; but in others a portion of the oxygen unites with the metal itself. This is the case when arsenic, molybdenum, tungsten, or selenium is employed. These metals are often acidified with the production of light. The acids render the oxygenated water more stable. Gold in a state of extreme division acts with great force on pure oxygenated water; yet it has no action on that liquid, if it be mixed with a little sulphuric acid.

M. Thenard took pure oxygenated water, and diluted it, so that it contained only eight times its volume of oxygen. He passed twenty-two measures of it into a tube filled with mercury. He then introduced a little fibrin, quite white, and recently extracted from blood. The oxygen began instantly to be disengaged from the water; the mercury in the tube sunk; at the end of six minutes the water was completely disoxygenated; for it no longer effervesced with oxide of silver. Having then measured the gas disengaged, he found it 176 measures = 8 × 22, that is to say, as much as the liquid contained. This gas contained neither carbonic acid nor azote. It was pure oxygen. The same fibrin, placed in contact with new portions of oxygenated water, acted in the same manner. Urea, albumen, liquid or solid, and gelatin, do not disengage oxygen from water, even very much oxygenated. But the tissue of the lungs cut into thin siices and well washed, that of the kidneys and the spleen, drive the oxygen out of the water, with as much facility, at least, as fibrin does. The skin and the veins possess the same property, but in a weaker degree. These results are equally interesting and mysterious.

WATER PEPPER, a species of polygonum. WATER PIMPERNEL, a species of veronica. WATER PIMPERNEL, ROUND-LEAVED. See SA

MOLUS.

WATER PLANTAIN. See ALISMA.

WATER PLANTAIN, LEAST, in botany, is a species of limosella; which, being omitted in its order, it is proper to describe here: Limosella, least water plantain, is a genus of the class of didynamia, and order of angiospermia; and in the natural method, ranking under the twenty-first order, preciæ. The plants of this genus, with all others of the same order, constantly have their seeds in a pericarpium: they have a simple stigma, and spreading corollæ. WATER POTS, in Spain, called Alcarazas, are earthen vessels, extremely porous, destined to cool the water for drinking, by means of the continual evaporation which takes place on their whole surface. Every house in Madrid is provided with these vessels, which are known to have been introduced into the country by the Arabs, and to be

equally used in Syria, Persia, China, Egypt, &c Those of Madrid are made of a kind of marly earth, found on the banks of the river Tanusoro, near the town of Auduxar, in Andalusia. On being care fully analysed it is found to contain about onethird of calcareous earth, a third of alumine, a third of silex, and a very small proportion of iron. The process for manufacturing the alcarazas is as fol lows:-After the earth has been dried, it is sepa parated into small lumps about the size of walnuts, which are thrown into a tub or vat, covered with water, and left to soak during twelve hours, after which it is kneaded. After it has been well wrought, it is spread in layers of about six fingers' depth on a smooth surface covered with brick, over which has been sprinkled a small quantity of sifted ashes. Here it is suffered to remain until it has become chapped: it is then cleared from the ashes, carried to a clean flagged floor, where it receives the addition of about the twentieth part of its weight of sea-salt, if intended for the fabrication of large jars, or only a fortieth if destined to be made into vessels of smaller size. An observant traveller says that a quantity of sand is also added. This mixture is kneaded anew with the feet, and then wrought on the wheel, after having been first carefully cleaned from any bits of straw or gravel which might have adhered to it. The vessels, when made, are placed in the potter's oven, but not more than half baked. It is to this circumstance, and to the marine salt which they contain, that they are indebted for their poro sity; for the very same earth is wrought into common pottery, without the addition of the salt, or the diminution of the baking. In the hottest weather, water put into one of these vessels, and placed in the open air, more particularly in a current of air, becomes in a very short time agreeably cool. In Estremadura, at a place called Salvatierra, are made red vases called bucaros, which serve also to preserve water cool. They impart to it a disagreeable clayey taste, which is, however, much admired by the women of Madrid. Girls are said to be parti cularly fond of this species of pottery, and eat it in the green sickness. Nearly similar vases are used in Portugal for moistening snuff, which is done by placing them in water after they have been filled with the snuff.

WATER PURSLANE, in botany. See PEPLIS.
WATER RADISH. See SISYMBRIUM.
WATER RAT. See Mus.

WATER ROCKET. See SISYMBRIUM. WATER SAIL, a small sail spread occasionally under the lower studding-sail, or driver-boom, in a fair wind and smooth sea.

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. See METEOROLOGY.

WATER VIOLET. See HOTTONIA.

WATERLAND (Dr. Daniel), a learned English divine who distinguished himself greatly in theological controversies, was born in 1633 at Wailsby, near Rasen, in Lincolnshire, of which his father, Erasmus Waterland, was many years rector. He was educated at Magdalen College, Cambridge, where he drew up a useful tract, which went through several editions, entitled Advice to a Young Student, with a method of Study for the first four years. In 1713 he became master of the college, was soon after appointed chaplain to George I., and in 1720 preached the first course of lectures

founded by lady Moyer in defence of our Lord's divinity. He went through several promotions, and at his death, in 1740, was canon of Windsor, archdeacon of Middlesex, and vicar of Twickenham. Besides his controversial writings, he published two volumes of sermons; but his chief work is his Vindication of the Doctrine of the Trinity, against Dr. Clarke; with his Defence of that work in reply to Clarke.

WATERLAND, an island in the South Pacific Ocean, discovered by Le Maire and Schouten, in 1616. It is represented as a low, sandy, uninhabited island, full of rocks, with plenty of trees on the border, but neither cocoa-nuts nor palmetoes. Some cresses and Indian salad were found, and some fresh water; but no soundings for anchorage were found. Long. 149° 30′ W., lat. 14° 46′ S. WATER-LODGED, the state of a ship when, by receiving a great quantity of water into the hold by leaking, &c., she has become heavy upon the sea, so as to yield without resistance to every wave rushing over her decks. As, in this dangerous situation, the centre of gravity is no longer fixed, but fluctuating, 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 her head under water. Hence there is no resource for the crew but to free her by the pumps, or to abandon her as soon as possible.

WATERLOO (Anthony), a famous Dutch painter, born at Utrecht in the sixteenth century. His paintings are admirably executed.

WATERLOO, a village of the Netherlands, ten miles south of Brussels, adjoins a spot where Marlborough, had he not been withheld by the Dutch deputies, might, in 1705, have defeated a French army, and have conferred on this village a similar renown to that attached to it since the memorable 18th of June 1815. We can only here afford space for a brief sketch of this memorable conflict. The forces engaged were, until late in the evening, nearly equal, the French reckoning 71,000 men, while the troops under lord Wellington were about 58,000; and those under Bulow, who came up early in the afternoon, were about 15,000 men. In regard to position, also, there was no great advantage, the ground on which the British were drawn up rising by a gentle ascent. In pursuance of his plan of diverting his opponents from the real attack, Buonaparte ordered an assault towards the right of the British, on the Chateau de Goumond, a post which, though hardly entitled to the name of a military station, was defended with such firmness that the French could gain possession only of the plantation, and failed in their attempts to drive the British from the position. This encounter, partial but sanguinary, took place between eleven and one o'clock. It was speedily followed by a more serious onset on the British left and centre. The British plan of battle, as regarded the infantry, was defensive; their battalions drawn up in squares, and protected by a number of field-pieces, awaited the attack; but their cavalry stood ready to seize any favorable opening to advance. This occurred, or was believed to occur on more than one occasion, in the early part of the battle; and conflicts took place with that varied result which will always prevail when, in armies of equal or nearly equal discipline, there remain regiments in reserve. A charge made by a body of British horse, on the flank of a French column, when marching from left to right,

was attended with great success; but this was soon ⚫ found to be dearly purchased; the field was covered with a number, apparently equal, of French and British uniforms; and the French cavalry were repulsed only by the arrival of a fresh body of British dragoons. On the part of the British infantry, the case was different; the defensive plan being strictly followed, the resistance was almost uniformly successful. The French generals witnessed a dreadful carnage; but observing that the British never advanced, and being unable to see clearly the whole of their battalions, they, in particular Ney, remained unconscious of their strength, and ventured between four and five o'clock to bring forward to the charge their cavalry reserve, the imperial guards. Twice did these intrepid horsemen rush on the British field-pieces and battalions. Though partially successful against the former, they failed against the latter; and being galled by their fire, both of cannon and musquetry, were obliged each time to retreat with great loss. This charge,' said Buonaparte, who stood on high ground at some distance, is too early by an hour.' Ney,' rejoined Soult, 'commits us as he did at Jena.' After two hours more of firing and partial attacks, Buonaparte thought it time to bring forward his final reserve, the imperial foot guard. This took place at seven o'clock, and brings us to the most remarkable juncture of the battle; that juncture in which, on almost every former occasion, whether against Austrians, Prussians, or Russians, the attack of a corps fresh and high spirited, caused the rout of the opposing line. Here, however, the British troops had been well supported; and, though fatigued, were not shaken. The blanks in their ranks (above 10,000 men had by this time been killed and wounded) had been successively filled by drafts from the reserve; and, if few expected victory, all were determined rather to fall than yield. Their general had higher hopes; he knew that the Prussians were approaching; and making the squares dissolve their order, and form into a continuous line, they obtained in their musquetry fire a great advantage over an enemy formed in close column. Affairs were now drawing to a crisis. Lord Wellington, observing the march of Blucher, ordered a forward movement; and the French, seeing on one side the British advance, on the other that the high road in their rear was on the point of being forced by the Prussians, relinquished the field of battle, and sought safety in a retreat, which soon became a disorderly flight.

WATERSAY, one of the Western Islands of Scotland, lying one mile south of that of Barray. It is three miles long and one broad, and pretty fertile. It has an excellent harbour, fit for sheltering vessels of any size, and in all weathers, from storms, being defended from all winds by the islands of Sanderay and Maldonich. It is inhabited by ten families; and belongs to Macniel of Barray. It lies about a mile from south Uist, from which it is separated by Christmas Bay.

WATERWORKS. See HYDRAULICS, and HYDROSTATICS.

WATFORD, a market-town and parish in Cashio hundred, Herts, on the banks of the Colne, eighteen miles and a half north-west from London. The Colne, which nearly surrounds the town, has several mills on its banks; but the principal manufacture is the throwing of silk, for which here is a very extensive machine, worked by water.