British title of nobility, next below a marquis, and above a vicount.

The title is so ancient, that its original cannot be clearly traced out. This much, however, seems tolerably certain, that among the Saxons they were called ealdormen, quafi elder men, signifying the same with senior or senator among the Romans; and also schiremen, because they had each of them the civil government of a several division or shire. On the irruption of the Danes they changed their names to corels, which, according to Camden, signified the same in their language. In Latin they are called comites (a title first used in the empire), from being the king's attendants; a societate nomen fumferunt, regis enim tales fibi afficiant. After the Norman conquest they were for some time called counts, or countees, from the French; but they did not long retain that name themselves, though their shires are from thence called counties to this day. It is now become a mere title; they have nothing to do with the government of the county; which is now en- tirely devolved on the sheriff, the earl's deputy, or vice- comes. In writs, commissions, and other formal instru- ments, the king, when he mentions any peer of the de- gree of an earl, usually styles him "truly and the well- beloved cousin:" an appellation as ancient as the reign of Henry IV.; who being either by his wife, his mo- ther, or his sisters, actually related or allied to every earl in the kingdom, artfully and constantly acknow- ledged that connection in all his letters and other pub- lic acts; whence the usage has descended to his suc- cessors, though the reason has long ago failed.

An earl is created by cincture of sword, mantle of state put upon him by the king himself, a cap and a coronet put upon his head, and a charter in his hand.

Earl-Marshal. See Marshal.

Earnest (arrhæ), money advanced to bind the parties to the performance of a verbal bargain. By the civil law, he who recedes from his bargain loses his earnest, and if the person who received the earnest give back, he is to return the earnest double. But with us, the person who gave it, is in strictness obliged to abide by his bargain; and in case he decline it, is not discharged upon forfeiting his earnest, but may be sued for the whole money stipulated.

Earth, among ancient philosophers, one of the four elements of which the whole system of nature was thought to be composed. See Element.

Earths, in chemistry, are defined by Cronstedt to be such substances as are not ductile, mostly insol- uble in water or oil, and that preserve their constitu- tion in a strong heat. Mr Bergman remarks that they are insipid, and not soluble in 1000 times their weight of boiling water; though, by augmenting the heat as in Papin's digester, perhaps all the kinds we are yet acquainted with may be found capable of solu- tion, especially when precipitated from some other medium; their surface being then greatly augment- ed. In the chain of nature they proceed by an insen- sible gradation towards the salts, so that they cannot be separated but by artificial limits. A moderate heat does not change their form, nor are they dissipated by a more violent one. Dr Black defines them to be such bodies as are not soluble in water, not inflammable, and their specific gravity not more than four times the weight of water. They are distinguished from the salts by their insolubility; from the inflammables, by their want of inflammability; and from the metals, by their deficiency in weight. Some objections have been made to this definition, as not being strictly applicable to those earths which are known to be soluble in wa- ter: but this objection may be accounted of little weight, when we consider the extreme disparity betwixt the solubility of the earths and salts, a few grains of the earths saturating some pounds of water; so that if they have any solubility, they must be allowed to pos- sess but a very small share of it.

Another property, which is not usually taken into the definition, makes nevertheless a remarkable part of the character of earthy bodies, viz. their great fix- edness in the fire. All the other classes of bodies show themselves volatile in more or less violent degrees of heat. All the salts can be made to evaporate; all the inflammable substances are volatile; all the metals, gold not excepted, have been converted into vapour; but the earths, as far as we know, have never been vo- latilized, excepting only two, the diamond and asbestos. Some phenomena attending the volatilization of the diamond give reason to suspect that it is not a pure earthy substance. There is an appearance of inflam- mation; and it seems to be a compound, having an earthy matter for its basis, and deriving its volatility from other matters. In general therefore, the earths have been found fixed in any degree of heat of which we have had experience; though there is no doubt a possibility, that heat might be raised to such an inten- sity as to volatilize the most fixed body in nature; but till the means of doing so shall be found out, the earths may be considered as absolutely fixed.

The earths called primitive or simple, because they cannot be decomposed by any method hitherto known, were by Cronstedt supposed to be nine; but later che- mists have reduced them to five. Some reduce the number still farther; but Mr Bergman informs us that these "rely their opinions upon fanciful metamorpho- ses unsupported by faithful experiments. As experi- ments teach us that there are five primitive earths, it is evident that the species arising from their mixture cannot exceed 24, viz. ten double, consisting of two earths; six triple; three quadruple, and the five pri- mitive earths. Even all these different mixtures have not been found, though they probably do exist in na- ture. The natural compositions of acids with the earths, forming substances not soluble in 1000 times their weight of boiling water, and which may be cal- led saline earths, are undoubtedly chemical combina- tions. The five primitive earths are, terra ponderosa; calx or calcareous earth, capable of being reduced into quicklime; magnesia; argilla or argillaceous earth; and siliceous earths.

"But though we must consider these as the most pure of all the earthy bodies, they are never found na- tive in a state of absolute purity; nor indeed can they be made perfectly pure even by artificial means. Wa- ter and aerial acid unite readily with the four first; and when expelled by fire, a little of the matter of heat is added, until driven out by a more powerful attrac- tion. But in this state they possess a degree of purity not to be attained by any other known method. There- fore it is necessary to examine them when sufficiently burnt, in order to distinguish better what properties depend upon adhering heterogeneous matters."

Our author at first added the earth of gems to the five classes already mentioned; but he found afterwards that all kinds of gems are compounded of some of the five kinds already mentioned, particularly of the ar- gillaceous kind, inasmuch that they may be said al- most entirely to belong to this class. Still, however, the earth of diamonds seems to possess properties ef- fectively distinct from the five already mentioned, and therefore may not unjustly be reckoned a sixth clas, though its characters have as yet been but very im- perfectly examined.

1. Terra Ponderosa. This was discovered in Sweden about the year 1774, and is found in several different forms.

1. Combined with aerial acid, called by Dr Wither- ing terra ponderosa aerata. This substance has been met with in England; and an account of it, with Dr Withering's analysis, is given under the article Chemistry.

2. The spar-like gypsum, marmor metallicum, lapis bononiensis, phosphorus nativus, baro-felenite, &c. is of very considerable specific gravity, approaching to that of tin or iron; on which account it has been supposed to contain something metallic. But no experiments hitherto made have evinced the existence of any metal in it, excepting a few traces of iron, which are to be met with in all the gypsas. It is met with of two kinds, semitransparent and opaque; the latter being either of a white or reddish colour. The specific gravity is about 4,500, water being accounted 1,000. It contains about 84 parts of ponderous earth, 13 of the most concentrated vitriolic acid, and three of water. The method of preparing the phosphorus from this substance is mentioned under the article Chemistry; but Cronstedt observes, that the phosphorescent quality of these stones is different from that of the sparry fluors and limestone, which is only produced by their being slowly heated, and seems to arise from a phlogiston which is destroyed by a glowing heat. M. Scheffer, in the Stockholm Memoirs for 1753, relates some experiments on a stone of this kind from China, which show that it is exactly the same with the petunse of that country, an ingredient in their porcelain manufactories. This stone does not burn into plaster as gypsum does, and is infusible by itself. It frequently contains calcareous earth, and sometimes is met with in the ores of metals, and it likewise forms the basis of some petrifications. Sometimes it contains one or two parts of iron in the hundred.

3. The marmor metallicum drusicum, or ponderous druse spar, is found in the lead-mines at Althomoor in Cumberland, regularly crystallized in the form of alum, solid, and semitransparent. M. Magellan says that he was showed some fine specimens of this mineral by a Mr Thomson, who informed him that "it seems to affect the peculiarity of having its crystals laminated, as radiating from a centre; but that this radiation seldom amounts to a whole circle. The corners of these flat crystals are truncated like those of alum, and thicker on one side than the other of the parallelogram, in such a manner as to fit one another in the kind of archet vault which they form together, and have some small ones adhering to their sides like druse spar, having internal angles, as the macles of the French, or the cruciform crystallizations." The specific gravity of these crystals were found by Mr Nicholson, with an instrument of his own invention, to be to water as 44,745 to 10,000. This species of crystals is found in Auvergne in France, and has been described by Mr Bayen, who supposed its basis to be calcareous. It was extremely refractory, and the surface of its crystals covered with ferruginous ochre. A variety of this is found jagged like cock's combs. This is met with in cliffs and fissures, accreted on the surfaces of balls of the same substance. In Derbyshire this substance is called coak or calk. M. Magellan was showed some specimens of it by Mr Whitehurst, which had not only convex but flat surfaces. Those of the upper aggregated parts were rather like the edges of very thin flattish lenses put together, than like cock's combs. Varieties of it are also found of white and reddish colours. It is likewise met with of a fibrous texture in the form of zeolite or albedos in filaments. M. Monnet is of opinion that these spars sometimes contain phlogiston, having observed that they become a liver of sulphur in a strong heat; but Mr Woulfe is of opinion that this gentleman was deceived by charcoal falling into his crucible.

4. The lapis hepaticus, or leberstein of the Germans and Swedes. Some specimens of this stone constantly smell like liver of sulphur, but others only when rubbed. It does not effervesce with acids, and according to M. Magellan is a medium between the gypsum and fetid calcareous stones with which it has generally been confounded; but it will not yield any lime, though the latter are more fit for the purpose than any other. Mr Kirwan informs us that this stone is generally compact, but not hard enough to strike fire; its texture is either equable or laminar, scaly or sparry; and it takes a polish like alabaster, does not effervesce with acids, and when calcined is partially reduced to a kind of plaster of Paris. According to the analysis of this stone, given us by Professor Bergman, 100 parts of it contain 33 of baro-felenite, 38 of siliceous earth, 22 of alum, seven of gypsum, and five of mineral oil. Cronstedt denies that these stones contain any volatile alkali, though his assertion is contradicted by Wallerius, who affirms, that a volatile alkali certainly exists in them, and may be discovered by a chemical analysis. "The method which nature takes to combine the ingredients of the lapis hepaticus (says Cronstedt), may be perhaps the same as when a limestone is laid in an heap of mud while it is roasting; because there the sulphur unites itself with the limestone, whereby the latter acquires the smell of liver of sulphur, instead of which the vitriolic acid alone enters the composition of gypsum. How the sulphur combines itself may likewise be observed in the slate-balls or kernels from the Andraram alum mines to be afterwards mentioned, where it sometimes combines with a martial earth with which this slate abounds, and with it forms pyrites within the very slate-balls. The fetid or twine stones, as well as the liver-stones, are, with regard to the structure of their parts, subject to the same varieties with the other kinds of limestones." This kind of stone is found, 1. Scaly, of which there are two varieties; one having coarse scales, the other of a whitish yellow colour. 2. With fine glittering scales. This is met with of a black colour at Andraram in Sweden, in the alum slate above mentioned. Bergman says that this kind consists of a ponderous earth combined with vitriolic acid, mixed with a rock oil, and with the calcareous, argillaceous, and siliceous earths. He adds, that by a chemical analysis one of these kernels gave 29 parts of caustic ponderous earth, 33 of siliceous, almost 5 of the argillaceous, and 3.7 of lime, besides the water and vitriolic acid which entered its composition.

II. Calcareous Earths, when freed from impurities as far as possible, have the following properties. 1. They become friable when burnt in the fire. 2. They more readily fall into powder by being thrown into water, or having it thrown upon them after calcination. 3. They cannot be melted by themselves into glaas in close They augment the causticity of alkaline salts by being mixed with them after burning.

They exhibit different phenomena in combination with the different acids. With the vitriolic they precipitate in the form of a gypseous earth capable of shooting, by proper management, into felenic crystals. With marine acid they form a deliquescent mass called fixed sal ammoniac, and which forms a kind of phosphorus. With nitrous acid they combine into a glutinous deliquescent mass, from which the acid may be partly driven off by fire; in which operation part of the earth itself is volatilized, and which, in a certain state of calcination, produces Baldwin's phosphorus. With the fluor acid they regenerate the spar from which this acid was procured. With phosphoric acid they are said to regenerate the earth of bones; though the experiments by which this is said to be proved are, as we have often had occasion to observe, by no means conclusive. With the acid of vinegar they crystallize into neutral salts, which do not deliquesce in the air. With borax they readily melt into a kind of glass which takes impressions in a degree of heat below ignition. With the microcosmic acid they likewise melt into glass with effervescence; a circumstance likewise observable when borax is made use of; and both these glasses are quite colourless and transparent while hot, but become opaque as soon as they cool; but if the head is thrown whilst hot into melted tallow, or even into warm water or any other hot liquor, it preserves its transparency. With flus-fat they melt more readily than with any other into a kind of flag, by which crucibles are corroded. This, however, according to M. Magellan, is entirely to be attributed to the solvents.

In certain cases they are likewise found capable of reducing some metallic calces, as those of lead and bismuth; sometimes also those of iron and copper are affected, though in a less degree. But on this Mr Kirwan remarks, that such reductions take place only when the earth is combined with aerial acid; and that though calces of lead are in some measure reduced by chalk, they are not in the least affected by lime; which evidently proves that they receive phlogiston from fixed air, which is a compound of phlogiston and dephlogisticated air.

In this last instance, as well as in some others, they resemble alkaline salts; whence they frequently take the title of alkaline earths. Mr Bergman observes, that as calcareous earth united to the aerial acid is found native, very little trouble is necessary to procure it in a state of purity. For this purpose nothing more is requisite than to boil selected pieces of chalk repeatedly in pure water, which dissolves any calcined earth or magnesia sativa that may be contained in it; after which operation it has no heterogeneous matter but what mechanically adheres to it, the quantity of which is generally extremely small; and if we likewise desire to have it absolutely free of this, we must dissolve it in vinegar, precipitate it with mild volatile alkali, and dry it after carefully washing the precipitate. The specific gravity of the precipitate thus carefully washed and dried is about 2.720. An hundred parts of it contain about 34 of aerial acid, 11 of water, and 54 of pure earth. Acids unite with it with effervescence, and the mixture produces heat. When burnt it loses 4% of its weight; and in this state dissolves in 700 times its weight of water, producing heat at the same time. If acids are poured upon it when in a calcined state, a great degree of heat is produced; infomuch that unless part of it be abstracted by previously mixing the earth with water, the mixture will be made to boil. The pouring of water upon calcined earth of this kind likewise expels the atmospheric air from its pores. In this case, if nitrous or muriatic acid be added, no effervescence will ensue; the solution will proceed slowly, but the saturation becomes at length as perfect as if the earth had not been calcined. By this burnt earth the acid is expelled from sal ammoniac, sulphur is dissolved, and other remarkable effects performed, of which an account is given under the articles Chemistry, Dyeing, Cement, Mortar, &c.

The calcareous earth, according to Cronstedt, is common to all the three kingdoms of nature; existing in the shells and bones of animals, the ashes of vegetables; and consequently, says he, it must have existed before any living or vegetable substance, and is no doubt distributed throughout the earth in a quantity proportioned to its general use.

The forms in which calcareous earth is ever met with are the shells of animals, chalk, limestone, and marble; for an account of which see these different articles. Its uses as a manure, and in building, are detailed under the articles Cement and Agriculture. Messrs Sage, Rome de L'Isle, &c. have supposed the existence of a kind of earth called abortent, distinct from the calcareous; but M. Monnet has shown this to be truly calcareous.

Magnesia, called also terra muriatica, or magnesia alba. The nature and properties of this earth are described under the article Magnesia. It is found,

1. Combined with the vitriolic acid in the form of a bitter salt called Epsom or Sedlitz salt. This is found in great plenty in the liquor which remains after the crystallization of sea-salt.

2. With the marine acid; in which case it forms a salt likewise crystallizable, but of a very hot burning taste, and emitting vapours of spirit of salt by distillation. This is known by the name of magnesia salina, and is likewise found in plenty in the liquor above mentioned.

3. It is contained also in fresh waters, where it is dissolved by the aerial acid.

4. Combined with the siliceous earth. This is commonly unctuous to the touch, and of different degrees of hardness, incapable of being diffused in water, and growing hard and very refractory in the fire. It is met with in various parts of the world, particularly in the east, and is the substance of which the large Turkey tobacco-pipes are made. It is also called French chalk, and is met with in England about the Land's End of Cornwall, of a yellow colour, or red and white like Castile soap. It consists, according to Mr Wiegbe, of equal parts of magnesia and siliceous earth. A mixture of this with calcareous earth and iron is found near Thionville in the French part of Luxembourg. It is of a blue colour, and contains the greatest proportion of calcareous earth, with some clay and petrified matters. Another of an olive colour is found in the same place; but has no argillaceous earth in it, though they... both look like clay, and the last is used in pottery. A mixture of this earth with clay, talc, and iron, is found in Silica. It is of a greenish yellow, is of a loose form and greasy feel. According to Mr Marmagran it contains one-third of magnesia.

5. In steatites or soap-rock. See Steatites. 6. In serpentine stone. See Serpentine.

IV. Argillaceous Earths. See Clay.

V. Siliceous Earths. See Chemistry, Flint, Gems, Diamond, Emerald, Sapphire, &c. also Chemistry, n° 829, 847, 1074, and 1076.