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GASOMETER, or GAZOMETER. A reservoir for holding a considerable quantity of gas. It is made of thin tinned iron plate, and mostly provided with some contrivance for measuring the quantity of gas it contains.

GAS, or GAZ. A name given by Van Helmont, and succeeding chemists, to all aerial fluids, except the common air.

at a red heat, and all the volatile products are conveyed by a common tube into a condensing vessel, which is kept cool by being immersed in water. In the condenser are retained the water, tar, and other condensible vapors, while the gaseous products, namely, the carburetted hydrogen, the sulphuretted hydrogen, and the carbonic oxyde and acid are passed through strata of slaked lime, by which the sulphuretted hydrogen and carbonic gases are absorbed, and the carburetted hydrogen and hydrogen gases in their purified state are transmitted into the gasometers, from which the several pipes are supplied that convey the gas to the lamps. The best kind of coal for distillation is that which contains most bitumen and least sulphur. After the discovery of obtaining gas from coal, attempts were made to extract it from other sub

It is supposed, that the gases, like vapors, owe their invisibility, elasticity, and capability of indefinite expansion, to caloric. The great Lavoisier, by adding two tubes to his calorimeter, contrived to make a known quantity of air to pass through the interior cavity, and to support combustion; and found, that when a pound of oxygen gas was made to combine with phosphorus in this manner, as much caloric was disengaged, as melted eighty-stances. The method of procuring it from oil is seven and a half pounds of ice.

It is owing to the strong affinity between caloric and oxygen, hydrogen, and azote, that these gases cannot be obtained in a concrete form. Were any substance discovered, that is possessed of a stronger affinity for caloric than these, it would be easy, by presenting it, to deprive them of their aerial form. If, for instance, hydrogen had a stronger affinity for caloric than the rest, and could be procured in a concrete state, by presenting it to the other gases, their bases might be deprived of the caloric with which they are united.

said to have originated in an attempt made in 1814 to convert coal tar into gas. Since that period, numerous works have been constructed for the manufacture of oil gas, which, in the opinion of many, is preferable to the coal gas.

GASTRIC JUICE. A fluid separated by the capillary exhaling arteries of the stomach, which open upon its internal tunic. The esophagus also affords a small quantity, especially in the inferior part. Modern philosophers have paid great attention to this fluid; and from their several experiModern chemists have given this name to bodies ments, it is known to possess the following properwhich have the appearance of air, though they do ties. It is the principal agent of digestion, and not possess all its properties. A gas is a compound changes the aliments into a kind of uniform, soft body, formed by the union of a basis, more or less paste. It acts on the stomach, after the death of solid, with caloric: thus, when the matter of heat the animal. Its effects show that it is a solvent; enters into combination with certain bodies, it vol- but of that peculiar nature, that it dissolves animal atilizes them, and reduces them to the state of and vegetable substances uniformly, and without It appears that all bodies do not require, indiscrim-exhibiting a stronger affinity for the one, than for inately, the same quantity of caloric, to assume the gaseous state and to reduce any substance to the state of gas, the application of caloric may be made in various ways. The more simple method consists in placing the body in contact with another body, which is heated. In this situation, the heat, on one hand, diminishes the affinity of aggregation, by separating the constituent principles to a greater distance from each other: on the other hand, the heat unites to the principles with which it has the be a little tinged with the yellow color of some bile, strongest affinity, and volatilizes them. Another that has regurgitated into the stomach. In quantimethod is, when one body is caused to act upon the extent of the surface of the stomach, and its ty, it is very considerable, as must be evident from another, to produce a combination, in which a dis- continual secretion; but it is the most copious, engagement of some gaseous principles takes place: for example, the sulphuric acid is poured upon the oxide of manganese; the acid combines with the metal, while its caloric seizes the oxygen, and rises with it. This principle takes place not only in this instance, but on all occasions, wherein, an operation being performed without the application of heat, there is a production of vapor or gas.

the other. It is far from being of the nature of a ferment, as many suppose; for it is one of the most powerful antiseptics we are acquainted with: and from the experiments of Spallanzani, Scopoli, Carminati, and others, its nature appears to be essentially different in the several classes of animals, of the human subject, when healthy, is inodorous, as they have proved by analysis. The gastric juice of a saltish taste, and limpid, like water, unless it

when solicited by the stimulus of food. Besides the properties of this fluid before mentioned, it has others, which have induced physicians and surgeons to exhibit it medicinally. It cures dyspepsy of fomentation or poultice, it cures putrid and and intermittent fever. Applied externally, in form scrofulous ulcers in a wonderful manner; and it is to be regretted, that its utility is not more generally known.

GAS LIGHT. Light produced by gas burning in lamps, &c. This gas, which is a combination GAUZE, or GAWSE. In Commerce, a very of oxygen and hydrogen, is carried away by pipes thin, slight, transparent kind of stuff, woven someand burnt at the orifice of escape. It is produced times of silk, and sometimes only of thread. The either from pit coal or whale oil. The process for gauze-loom is like a common one, but with some producing coal gas is as follows. The coal, being appendages. There are figured gauzes, and some broken to a convenient size, is placed in oblong with flowers of gold and silver, which last are cast iron retorts, ranged in furnaces to keep them | chiefly brought from China.

GAZELLE. A beautiful species of the Antelope frequently alluded to, in Persian poetry.

GAZETTE. A newspaper. The first gazette is said to have been printed in Italy, at Venice, in the year 1536; and to have derived its name from the name of a little coin called gazetta, which was the common price of one of these papers. The first regular gazette published in England was in 1622, entitled 'The certaine News of the present Weeke.' The first gazette in France was in 1631; the first in America was the Boston News Letter, commenced at Boston, 1704, by B. Green; the first in Pennsylvania was in 1719; the first in New York was in 1725; the first in Rhode Island was in 1732; the first in Connecticut was in 1755; and the first in New Hampshire in 1756. The number of papers, issuing annually from the presses in Great Britain, at the close of the 18th century, are computed to have been considerably more than fifteen million.

GAZETTEER. A writer or publisher of a Gazette; also the title of a geographical dictionary.

GELATINE. In Chemistry, is one of the constituent parts of animal substances, and may be obtained by repeatedly washing the fresh skin of an animal in cold water, afterwards boiling it, and reducing it to a small quantity by slow evaporation, and allowing it to cool. It then assumes the form of jelly, and becomes hard and semitransparent. It is a principal ingredient both of the solid and fluid parts of animals, and is employed in the state of glue, size, and isinglass. Gelatine is used in a new kind of bread, called pain animalisé, now manufactured in Paris. It having been found that the gelatine of bones used for soups was exceedingly nutritious, it was imagined that if this gelatine could be introduced into bread from potato flour, which is very much less nutritious than wheaten flour, the former would be equally pleasant, and even more nutritive than wheaten bread. The experiment has been tried with great success; and beautiful loaves of bread, made in this way, are now sold in Paris at a much lower price than bread from wheat flour.

GEM. In the natural history of fossils, a common name for all precious stones, of which there are two classes; the pellucid, and semi-pellucid.

The pellucid gems are compound bodies, extremely hard, and of great lustre. The semipellucid gems are composed of crystalline matter, slightly debased with earth.

The knowledge of gems depends on observing their hardness and color. Their hardness is commonly allowed to stand in the following order: the diamond the hardest of all; then the ruby, sapphire, jacinth, emerald, amethyst, garnet, carneol, chalcedony, onyx, jasper, agate, porphyry, and marble. This difference, however, frequently

varies.

and porphyry, for their vermillion, green, and variegated tints; and the garnet, for its transparent

red.

All these gems are sometimes found colored and spotted, and sometimes limpid and colorless; in which case, they are known from each other by degrees of hardness.

The semi-pellucid gems are frequently mentioned, on account of the figures, portraits, and emblems engraved on them, in both ancient and modern times.

GENDARMES, or GENS D'ARMES. A select body of soldiers in the French army, who are now much employed by the police.

GENDER. In Grammar. A distinction in nouns to mark the sexes; genders are either masculme, for the male sex; feminine, for the female sex; or neuter, for those which are of neither sex.

GENEALOGY. Is more particularly a series or succession of ancestors, or progenitors; or a summary account of the relations and kindred of a person, or family, both in the direct and collateral lines.

The Jews were anxious to preserve their genealogies entire and uninterrupted; and this care on their part affords an argument of considerable importance with respect to the accomplishment of those prophecies that pertain to the Messiah. Accordingly, in their sacred writings, we find genealogies carried on for above thirty-five hundred years. It is observed (Ezra ii. 62) that such priests as could not produce an exact genealogy of their families were not permitted to exercise their functions. Josephus says that they had, in his nation, an uninterrupted succession of priests for two thousand years; that the priests were particularly careful to preserve their genealogies, not only in Judea, but also in Babylonia and Egypt; and that, wherever they were, they never married below themselves, and had exact genealogical tables prepared from those authentic documents which were kept at Jerusalem, and to which they had recourse; and that, in all their wars, persecutions, and calamities, they always were diligent in securing those documents, and in renewing them from time to time. Jerome says (ad Tit. iii.) that the Jews know so perfectly the genealogies, that they can repeat all the names from Abraham to Zerubbabel, as easily as their own. Nevertheless, since the war of the Romans against the Jews, about thirty years after the death of our Saviour, and since their entire dispersion in the reign of Adrian, the Jews have lost their ancient genealogies; and perhaps there is not even one of the sacerdotal race who can produce authentic proofs of his genealogy. This circumstance has been alleged by Christian writers as a presumptive proof of the actual advent of the Messiah, whose genealogy, corresponding to ancient predictions, the Jews are no longer able to trace, and consequently of the truth of Christianity.

In point of color, the diamond is valued for its transparency: the ruby, for its purple ; the sapphire, GENERAL. The highest rank in an army, in for its blue; the emerald, for its green; the jacinth, which they are successively major-generals, lieufor its orange; the amethyst-carneol, for its carna- tenant-generals, and generals, according to seniority, tion; the onyx, for its tawny; the jasper, agate, when promotions are made.

GENERICAL NAME. In Natural History, earth in general, and the affections common to the the word used to signify all the species of natural whole globe, as its figure, magnitude, motions, bodies, which agree in certain essential and peculiar circles, winds, tides, meteors, divisions into land characters, and therefore all of the same family or and water, &c. Particular geography has respect kind; so that the word used as the generical name, to particular countries, showing their boundaries, equally expresses every one of them; and some figure, climate, seasons, inhabitants, arts, customs, other words, expressive of the peculiar qualities or language, history, &c. When it respects regions, figures of each, are added, in order to denote them districts, or parts of countries, it is called chorogsingly, and make up what is called the specific raphy, and when particular cities, towns, or villages, &c. it is called topography. Particular geography is also distinguished into ancient geography, when it treats of the countries and places existing among the ancients; modern geography, when it treats of modern places; the geography of the middle ages, which treats of places that flourished in the middle ages; and lastly, sacred geography, which treats of places mentioned in the Bible.

name.

GENEVA, or GIN. A hot, fiery spirit, much used by the lower classes of people as a dram, and unquestionably most injurious to their constitution and morals. A liquid of this kind was formerly sold in the apothecaries' shops, drawn from the juniper berry; but distillers have now completely supplanted the trade of the apothecary, and sell it under the name of geneva or gin, of which, it is believed, juniper berries make no part of the composition. It is composed of oil of turpentine and malt spirits. A better sort is said to be drawn off, by a slow fire, from juniper berries, proof-spirits and water, in the proportion of three pounds of berries to four gallons of water and ten of spirits. The celebrated Holland geneva is manufactured chiefly at a village near Rotterdam, from the same materials, French brandy being used instead of malt spirits.

GENIUS. In ancient superstition, a spirit, who presided over the affairs of nations or individuals. In tine, each nation pretended to have a god, or providence, attentive to its peculiar prosperity, and hostile to the pretensions of others. Here we easily see one great opening to polytheism. Another was, that each individual begun to have his separate providence. It has ever been a prevailing idea with the professors of various religions, that the Deity transacts all the affairs of this world, and even created it, by commission; and the commissioners were genii.

Among the Mohammedans, genii occupy a rank in existence, between those of men and of angels; more powerful than the former, but less spiritual than the latter.

GENTILES. A name given by the Jews to all who were not of the twelve tribes of Israel; among Christians, it is the name of all heathens who did not embrace the Christian faith.

GENUS. In Natural History, a subdivision of any class or order of things, whether animal, vegetable, or mineral kingdoms. All the species of a genus agree in certain characteristics.

GEOCENTRIC. In Astronomy, is applied to a planet, or its orbit, to denote it concentric with the earth; or as having the earth for its centre, or the same centre with the earth.

GEOGRAPHY. The science which treats of the earth as an habitable world, comprehending a description of the whole globe, together with an account of all its parts, limits, inhabitants, &c. Geography is either general or particular. General geography comprehends the knowledge of the

The earth, considered as a planet, is supposed to be marked by circles corresponding to those which the sun apparently describes in the heavens, as the horizon, which divides the sphere into two parts or hemispheres, the one upper and visible, the other lower and invisible; the equator, which is equidistant from both the poles, and divides the globe into northern and southern hemispheres; the azimuth, or vertical circles, which intersect each other at the zenith and nadir; the meridian, which crosses the equator at right angles, and from which the distance of places east and west is reckoned; the parallels of latitude, small circles supposed to be parallel to the equator, which show the latitude of places, or their distance north and south from the equator; the arctic and antarctic circles, two circles at the distance of twenty-three degrees and a half from the north and south poles; the two, tropics, namely, the tropic of Cancer and the tropic of Capricorn, the first north and the second south, twenty-three degrees and a half distant from the equator; to these might be added the hour circles, or the twenty-four circles passing through the equator, and corresponding to the twenty-four hours of the day.

From the diversity in the length of the days and nights, geographers divide the globe into certain districts, called climates, measured either by hours or half hours; and from the effects of light and heat upon the earth in different parts, it is distinguished into five zones, namely, one torrid or burning zone, between the tropics; two temperate, between the polar circles and the tropics; two frigid or frozen zones, between the polar circles and the poles. The inhabitants of the earth, as to their relative situation in regard to each other, are distinguished into the antipodes, who live directly opposite to each other; the antoeci, who live under the same meridian, but opposite parallels of latitude; the perioeci, who live under the same parallels of latitude, but opposite meridians.

The earth is naturally divided into land and water, and according to some computations about three-fourths of it is occupied by water, and the remaining fourth by land. The land is distinguished into continents, or large portions not separated by any sea, as the four great continents, Europe, Asia, Africa, and America, which are the four quarters of the world; islands, smaller portions, entirely surrounded by water, as Great Britain, Ireland, &c.; peninsulas, or tracts of land almost

surrounded by water, as the Morea, in Greece; bottom, the east on the right and the west on the isthmuses, or necks of land joining two continents, left. Maps are always laid down according to a as the isthmus of Suez, joining Africa to Asia; certain scale, taken from the degrees of latitude promontories, or capes, high portions of land which are marked on the east and west side of the stretching out into the sea, as the Cape of Good map, those of longitude being marked on the north Hope; mountains, or elevations of the earth's sur- and south side. As the earth is a globe, a map of face, such as the Alps and Pyrenees in Europe, the the whole earth must necessarily consist of two Caucasus and Uralian Mountains in Asia, and the parts, both sides of the globe not being visible at Andes in America. The water is distinguished once; accordingly in a universal map the right into oceans, which are vast collections which sepa- hand circle shows the old world, that is, Europe, rate the continents from each other, as the Pacific Asia, and 'Africa, and the left hand circle the new and Atlantic Oceans; seas, or smaller collections world, or America. Upon the general map are of water, as the Indian Sea, Black Sea, &c.; gulfs, marked the circles correspondent to those of the parts of any sea surrounded nearly with land, as sphere, as the equator, &c. Particular maps, being the Gulf of Venice, if they have a wide entrance parts of this globe, retain the meridians and paralthey are bays, as the Bay of Biscay; straits, nar- lels belonging to the particular part, which are row passages joining two seas, as the Strait of made smaller or larger according to the size of the Gibraltar; lakes, large collections entirely sur-map, and the distance of the places mentioned are rounded by land, as the Lake of Geneva; rivers, proportioned to the breadth of the parallels as streams of water which have their source in some nearly as they can be. spring, and empty themselves into some other river or piece of water. The principal rivers, as to their magnitudes, are the Amazons, Senegal, Nile, St. Lawrence, La Plata, Mississippi, Volga, Oronooko, Ganges, Euphrates, Danube, Don, Indus, Dnieper, and Dwina, but if estimated according to the length of course which they run, their order will be rather different, but the Amazons is the largest in every respect.

In maps the sea is denoted by an open space, the thick shadowing denotes the sea-coast, rivers are marked by shadowed serpentine lines, if large by double and treble lines made strong and black, roads by double lines, divisions of countries by dotted lines, and sometimes distinct colors, those for kingdoms and provinces being larger than the rest; forests are represented by trees, mountains by rising shadows, sands by dotted beds, lakes by shadowed coasts, rocks by pointed things sticking

arrows. The names of villages are written in a running hand, those of towns in a Roman character, those of cities in small capitals, and those of provinces in large capitals. Cities or great towns are made like small houses, with a little circle in the middle of them, but smaller towns or villages are marked only with little circles; bridges by a double line across the river. In some maps, particularly old maps, cities, as the sees of bishops, were marked by a cross or mitre, and those of archbishops with a double cross, universities with a star or a caduceus, abbeys with a crook or pastoral staff, fortresses with an angle, as of a bastion, castles with a little flag, gentlemen's seats with a single house only, &c.

The earth is politically divided into countries, which, according to their government, are distin-up sharp in the sea, the course of the winds by guished into empires, if they are of great extent, as the Russian and Austrian empires; or kingdoms, as the kingdoms of great Britain, France, Spain, &c.; or states, as the states of Holland and America; or republics, as the republics of Venice, Genoa, &c. Under this head geography treats of the subdivisions of each country into provinces, cities, towns, &c.; also of the number of inhabitants, the nature and produce of the soil, the animals peculiar to each place, the state of the arts, manufac ́tures, commerce, &c. which constitute the wealth of each country, and is comprehended under the name of statistics. To all this may be added an account of curiosities, natural and artificial, as volcanoes, caverns, canals, springs, fountains, and the like. Besides, geography treats not only of the earth's surface, but also of the affections which it is exposed to from the waters of the ocean which produce the flux and reflux of the tide, and the currents belonging to particular seas, as in the Mediterranean and Euxine seas; likewise of the winds which blow in particular manners and directions, such as the monsoons or trade winds, which blow for some months in the year one way and the rest another; and, lastly, the meteorological Reculiarities of each country, such as regards the degree of heat and cold, the quantity of rain which falls in particular places, or within a given period, the duration of frosts, and other particulars respecting the climate, and its effects upon the surround-es which it has undergone. ing objects.

The apparatus called the terrestrial globe, has a complete map of the earth drawn on its surface, with the several imaginary circles, and is moreover fitted to illustrate the movements of the earth as a planet, the latitudes, longitudes, and distances of places, the hours of day and night in different parts, with a number of other interesting problems.

GEOLOGY. Has for its object the structure and formation of this globe: it, of course, embraces the consideration of the materials of which it is composed, and the circumstances peculiar to its original formation, as well as the different states under which it has existed, and the various chang

It necessarily follows, from the very limited depth Geographical descriptions are moreover illustrat- within which our actual examinations have been ed by engraved delineations, which when they re-made, that our facts and real observations are conpresent an ocean, sea, or any piece of water, is called a chart, but when they represent any parts of the earth generally are termed maps. In all maps the north is at the top and the south at the

fined to what may be considered, comparatively, as merely the crust of the globe. With respect to its more internal part, we have hitherto only been aided by conjecture, which, it must be admitted,

has too frequently led to theories, the most extrav-| being now buried beneath its waves. In explanaagant and absurd. From the experiments of sev- tion of this varying evidence, it is necessary to state, eral learned men, it, however, appears, that the although it may not affect the general question, density of the globe is greatest towards its centre. that it cannot be doubted, that whilst the land is Boscovich is of opinion, from his very ingenious gaining on the sea in some parts, similar encroachcalculations, that the centre is a spherical nucleus, ments are observable in others, of the sea on the possessing an equal degree of density to within dry land. Instances of this, on the small scale, some leagues of the earth's surface; but although it is thus concluded, that the interior of the earth is solid, contrary to the conjectures of several ancient philosophers, yet it is by no means pretended, that even in this, its more solid parts, there may not exist cavities of a greater or less size, connected, perhaps, with each other, and extending considerably, in all probability, towards the surface.

allow of their removal by the waves: thus is occasioned a considerable reduction of the level of the shore, and thus an opportunity is given for the extension of the waters of the ocean on some particular spots. The balance, however, of this seemingly contradictory evidence is undoubtedly in favor of the opinion, that the water has considerably diminished, and is, perhaps, lessening at the present period.

may be observed on almost all flat, and on many precipitous shores; on the former, large embankments of sand are sometimes suddenly thrown up by considerable and violent inundations, and which, in consequence of alteration in the shape of the coasts, and of the direction of currents, may still remain, and appear to manifest an increase of the dry land: on precipitous shores, the reverse of this The solid masses of the globe, which have come is observable: undermined by the continual and within our examination, have been distinguished powerful action of the waves, large masses are into primitive and secondary; among the former perpetually falling, and broken by their fall and by were placed the rocks of granite, gneiss, porphyry, the action of the water, are so reduced as to easily serpentine, and limestone, of a peculiar character; and, among the latter, were considered the rocks of secondary limestone, of phosphate of lime, of gypsum, and of some of the sand stones; of chalk, and of silex. This division is not, however, at present universally adopted; other divisions having been assumed, which have appeared to agree better with the different systems which have been proposed. These divisions we shall therefore more fully notice, after pointing out the peculiarities of these several systems. The water is supposed, at present, to cover about three-fifths of the whole earth, but undoubted evidence exists, of its having extended over a much wider surface, and it is the opinion of many of the most eminent geologists, of its having covered the whole of the earth. As the necessity of ascertaining this latter circumstance is much urged, by those who have endeavored to form correct opinions respecting the mode in which this globe was originally formed, it will be proper here to notice some of the evidence which has been adduced respecting this circumstance.

Herodotus relates, that, according to the priests of Vulcan, the whole of Egypt, except in the neighborhood of Thebes, had been covered with water. Herodotus himself also noticed the existence, even in his time, of lakes of salt water in different parts of Egypt, as well as of the saline matter, mingled with the vast tracts of sand with which that country is covered; which observations are confirmed by the accounts that have been given by those who have examined these parts in modern times. The diminution of the ocean is also rendered in the highest degree probable, from various facts related also by Strabo, Pliny, Diodorus the Sicilian, and several other early writers; and in the present day, the observations of Pallas, Celsius, Linnæus, and others, seem to establish the fact of the diminution and sinking both of the Baltic and of the Caspian Seas.

On the other hand, innumerable facts may be adduced which seem to prove that the water has actually increased in its proportion, over the dry land. From the relations of Plaucus, Bryden, Barral, Fortis, and others, there can no doubt exist of the Mediterranean Sea having very much encroached on its shores; temples, and other edifices of different descriptions, which are known to have been erected at considerable distances from the sea,

Indubitable evidence of the water having stood over tops of mountains, which are at present much above the level of the ocean, is yielded, by the circumstance of various organized beings, former inhabitants of the water, being imbedded in these mountains and even in their summits. Those who contend that the whole of the earth has been covered with water, have recourse to the testimony afforded by the several chemical and physical properties, discoverable in the component parts of the loftiest mountains; and, which prove in their opinion, that all these substances have obtained their origin from the waters of the ocean, which they suppose to have invested the whole earth. This mode of the formation of rocks will not, however, be admitted by every geologist, to be sufficiently ascertained to allow of its being adduced as an evidence on the present occasion. That they have been thus produced there appears, however, to be the greatest reason for supposing; but as their origin still remains a question with many, the testimony on this occasion must be proportionally weakened.

In the following sketch of some of the most interesting and important systems of the formation of the world, several facts will be noticed, from which additional evidence will be adduced of not only the formation of the rocks from the contents of the primitive waters, but also of the waters having totally covered the earth; and since most of the important geological facts will come into consideration, whilst taking a view of the different systems which have been offered of the formation of the world, and of the several changes which it has undergone, it is proposed to appropriate the remaining part of this article to that purpose.

Omitting to notice any further the scriptural account of the creation of the world, merely on account of the brevity of the narration preventing the disposal of events there related in a systematic

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