The medical effects of this preparation in small quantities are sudorific; in larger doses a purgative and emetic. ETHIOPS VEGETABILIS is prepared by burning the sea-wrack or sea-oak in the open r, and then reducing it into a black powder. It is used in scrophulous swellings, and in dansing the gums and teeth. ETHMOID ARTERY and BONE. See ETHMOID ARTERY and BONE. ETHNA. (, æthuna, a furnace, Heb. , from alw, to burn.) 1. A subterraneous fre 2. A chemical furnace. ETHORES, or ÆTHOLICES. (from aw, to bura.) Hot cutaneous pustules. ETHUSA MEUM. The systematic name for the meum athamanticum; which see. ETBU'SA. Lesser hemlock, or fool's-parsley. A genus of the class and order pentendria digyna. Its fruit is striate, involucrets halved, three-leaved, pendulous. There are three speces, of which the A. cynapium, with uniform leaves, is common to our own corn-fields. ETIA. (aria, a cause.) In medicine, the case of a disease. AETIANS, in church history, a branch of Arians, who maintained, that the Son and Holy Gare in all things dissimilar to the Father. ETIOLATION, a term denoting the state vetables which, by growing in the shade, ting deprived of light, become pale, , and insipid. How this change is proCd, the present state of our knowledge will permit us to explain; but it is a fact of eral observation, that the colour of herbs pale or deep in proportion as they are less or we exposed to the rays of the sun; and those which, for the want of those rays, are pale or white, are said to be ætiolated, from a French word signifying star, as if they grew by starIght. See COLOURS. ETIOLOGY. (atiologia, aızıɔkoysa, from , a cause, and hoyos, a discourse.) The ctrine of the causes of diseases. AETION, a celebrated painter, who has it us an excellent picture of Roxana and Alexander, which he exhibited at the Olymgames: it represents a magnificent chamer, where Roxana is sitting on a bed of a inst splendid appearance, which is rendered sul more brilliant by her beauty. She looks downwards, in a kind of confusion, being strick with the presence of Alexander stand g before her. A number of little Cupids Fatter about, some holding up the curtain, as il to shew Roxana to the prince, whilst others busied in undressing the lady; some pull Alexander by the cloak, who appears like a yung bashful bridegroom, and present him to is mistress: he lays his crown at her feet, being accompanied by Ephestion, who holds a torch in his hand, and leans upon a youth, who represents Hymen. Several other little Cupids are represented playing with his arms; the carry his lance, stooping under so heavy a weight, others bearing along his buckler, upon which one of them is seated, whom the fet carry in triumph; another lies in ambush in his armour, waiting to frighten the rest as they pass by. This picture gained Action so much reputation, that the president of the games gave him his daughter in marriage. ÆTIOR PHLEBES. (from Ming, an eagle, and pr↓, a vein.) Eagle veins an appellation given by Ruphus Ephesius to the veins which pass through the temple to the head in animals generally; but which in eagles are peculiarly prominent. ETITE, or ETITES, a name given to pebbles or stones of any kind, which have a loose nucleus rattling within them, and called in English cagle-stones. So far from being a particular genus of fossils themselves, we find ætitæ among very different genera, but the most valued is that formed of the several varieties of our common pebbles. AETIUS, one of the most zealous defenders of Arianism, was born in Syria, and flourished about the year 336. After being servant to a grammarian, of whom he learned grammar and logic, he was ordained deacon, and at length bishop, by Eudoxus patriarch of Constantinople. St. Epiphanius has preserved 47 of his propositions against the Trinity. His followers were called Aetians. ETNA. (in the itineraries Ethana, supposed froin aw, to burn; according to Bochart, from Athuna, a furnace, or Etuna, darkness, now Monte Gibello.) A volcano or burning mountain of Sicily, situated in lat. 38. N. long. 154. E.-This mountain, famous from the remotest antiquity both for its bulk and terrible eruptions, stands in the eastern part of the island, in a very extensive plain, called Val Demoni, from the notion of its being inhabited by devils, who torment the spirits of the damned in the bowels of this volcano. Authors are not agreed as to its dimensions, or its height above the surface of the sea. The accounts given of the phænomena which have accompanied its eruptions, by sir William Hamilton and Mr. Brydone, are exceedingly interesting. According to the observations of the last-mentioned traveller, the height of Ætna is about 12,000 feet. Faujas de S. Fond states it at 10,036 feet. The circumference of the base is commonly reckoned about 180 miles. There are 77 cities, towns, and villages, scattered over different parts of the sides of this mountain, and the number of its human inhabitants above 100,000. The distance from Catania to the summit exceeds 30 miles. The fire which is continually burning in the bowels of this mountain led the poets to place here the forges of the cyclops, under the direction of Vulcan, and the prison of the giants who rebelled against Jupiter. The eruptions of this mountain have likewise been described by several of the ancient poets, as Pindar, “Virgil (neid, b. iii. v. 571), and Lucretius (lib. vi, v. 639). Pindar in the fifth decade of an ode which was composed in the 78th Olympiad, about four or five years after the second erup tion mentioned by Thucydides, has a passage thus translated by West. Now under sulph'rous Cuma's sea-bound coast, ments pour. The last two eruptions of this volcano we have seen described, took place in July and October, 1787. In the latter of these the stream of lava that issued from the crater was three miles long, about a quarter of a mile broad, and from five to eighteen feet deep. ETNA SALT, Sal Etna, a name given by some to the sal ammoniac, which is found on the openings of Etna, and other burning mountains; and sometimes on the surface of the matter thrown out during an eruption. It is sometimes found in cakes, and sometimes in powder; and its colour is either green, yellow, or white. This salt is composed of nitre, sulphur, and vitriol, and is supposed to be formed during the burning of the mountain. AFFECTED, in algebra, is sometimes applied to equations in the same sense as adfected. Algebraic quantities which have coefficients, or any of the characters +, &c. prefixed, are also said to be affected with the co-efficient, or respective sign. AFFECTEDNESS. s. (from affected.) The state of being affected. AFFECTION, in a general sense, implies an attribute inseparable from its subject. Thus magnitude, figure, weight, &c. are affections of all bodies; and love, fear, hatred, &c. are affections of the mind. AFFECTION, signifying a settled bent of mind toward a particular being or thing, occupies a middle space between disposition, on the one hand, and passion on the other. It is distinguishable from disposition, which being a branch of one's nature, originally, must exist before there can be an opportunity to exert it upon any particular object; whereas affection can never be original, because, having a special relation to a particular object, it cannot exist till the object have once at least been presented. It is also distinguishable from passion, which, depending on the real or ideal presence of its object, vanishes with its object; whereas affection is a lasting connection; and, like other connections, subsists even when we do not think of the person. Dr. Cogan, in his Philosophical Treatise on the Passions, very properly distinguishes between affection and passion; and he accurately discriminates between both these terms, and that feeling which is usually denominated emotion. The term affection, he says, has a different signification from either of the other two, and represents a less violent, and generally a more durable influence, which things have upon the mind. It is applicable to the manner in which we are affected by them for a continu ance; and supposes a more deliberate predilection and aversion, in consequence of the permanent influence of some prevailing quality. This distinguishes it from the transient impulse of passion; nor is it so intimately con nected with any external signs, which distinguishes it from emotions. The affections sometimes succeed to passions and emotions, because these may have been excited by something that becomes permanently interesting; or they may be gradually inspired, by a deliberate attention to the good or bad qualities of their objects. In this philosophic sense of the word, affection is applicable to an unpleasant as well as pleasant state of the mind, when impressed by any object or quality: it may be produced by any thing that torments or corrodes the heart, as well as by that which charms and delights it. Custom, however, chiefly appropriates the term to the kind and benevo lent affections. Cogan on the Passions, p. 10. AFFECTION. (affectus, or affectio, from afficio, to disturb.) In medicine, a peculiar disposition of the mind or body to disease or health. AFFECTIONATE. a. (affectionné, Fr. from affection.) 1. Full of affection; warm; zealous (Sprat). 2. Fond; tender (Sidney). 3. Benevolent; tender (Rogers). AFFECTIONATELY. ad. (from affectionate.) Fondly; tenderly; benevolently. AFFECTIONATENESS. s. (from affectionate.) Fondness; tenderness; good-will. AFFECTIONED. a. (from affection.) 1. Affected; conceited: obsolete (Shakspeare). 2. Inclined; mentally disposed (Rom.). AFFECTIOUSLY. ad. (from affect.) In an affecting manner. AFFECTIVE. a. (from affect.) That does affect; that strongly touches (Rogers). AFFECTUOSITY. s. (from affectuous.) Passionateness. AFFECTUOUS. a. (from affect.) Full of passion: little used. AFFERORS, AFFERATORES, in law, persons appointed in court-leets, and other places, upon oath, to settle and moderate the fines of such as have committed faults arbitrarily punishable, or which have no express penalty set down by statute. See Stat. 25 Edw. III. cap. 7. AFFETTUOSO, or CON AFFETO, in the Italian music, intimates that the part to which it is added ought to be played in a tender affecting way; and consequently rather slow than fast. AFFI'ANCE. s. (affiance, from affier, Fry 1. A marriage contract (Spenser). 2. Trust in general; confidence (Shaks.). 3. Trust in the divine promises and protection (Atterb.). To AFFIANCE. v. a. (from the noun.) 1. To betroth; to bind any one by promise to marriage (Spens.). To give confidence (Pope AFFI'ANCER. s. (from affiance.) He that makes a contract of marriage between two parties. AFFIDATION. AFFIDA'TURE. s. (from affido, Lat. See AFFIED.) Mutual contract; mutual oath of fidelity. AFFIDAVIT. s. (affidavit signifies, in the language of the common law, he made oath.) A declaration upon oath (Spectator). AFFIED, particip. a. (from the verb affy, derived from affido.) Joined by contract; affianced (Shakspeare). AFFILIATION. s. (from ad and filius, Lat.) Adoption; the act of taking a son (Chambers). AFFINAGE. s. (affinage, Fr.) The act of refining metals by the coppel. AFFINDRA. (apipa, from apidjaw, to perpire) Ceruss. In ancient medicine, so named from a power ascribed to it of promoting perspiration, a quality for which it is never employed in modern times. AFFINED. a. (from affinis, Lat.) Related to another (Shakspeare). AFFINITY. s. (affinité, Fr. from affinis, Lat.) 1. Relation by marriage. 2. Relation to; connection with. The Romanists talk of a spiritual affinity, contracted by the sacrament of baptism and confirmation. In that church, a god-father may not marry with his goddaughter, without a dispensation. Affinity does not found any real kinship; it is no more than a kind of fiction, introduced on account the close relation between husband and we. It is even said to cease, when the cause a ceases. Hence a woman who is not caof being a witness for her husband's bro, during his life-time, is allowed for a wit, when a widow, by reason the affinity is olved. Yet with regard to the contracting marriage, affinity is not dissolved by death, though it be in every thing else. AFFINITY, in the civil law, is divided into cil, that between free persons; and servile, that between slaves. AFFINITY, in natural philosophy, 1. The tendency which the particles of matter have to be attracted or united to each other. 2. Elective attraction (in chemistry) simple, reciprocal, or double. 3. Sympathy or consent of parts (in physiology.) The power by which one organ is affected by another, whether directly or inversely. See SYMPATHY. AFFINITY, chemical, is that power by which the particles of different bodies are combined, so as out of two or more substances to form one uniform whole, which is not decomposable by mechanical means, and the properties of which are often different from those of the substances of which it is formed. This affinity exists in very different degrees among different bodies, and its varieties are among the most wonderful objects of chemical research. The term is synonymous with the elective attraction of Bergman, and is called by some other chemists the attraction, or affinity of composition. Like many other terms, in common as well as scientific language, it is of metaphorical origin; and in this sense may be called the series of relationships between simple substances. From the appearance of certain external characters of resemblance between different animals, zoologists have contended for the existence between them of certain natural connexions, or family relationships; and have hence systematically arranged the animal kingdom into distinct tribes or families. From a similar appearance among plants, a similar system has been adopted by botanists. From the appearance of certain internal powers of reciprocal attraction between bodies of a simpler and more elementary form, chemists have, in like manner, contended for a similar series of connexions or relationships between these last, and to these connexions or relationships they have given the name of affinities. Chemical affinity may, therefore, be regarded as the principle of chemical action: chemical attraction as the same principle in a state of operation, by which alone the degree of affinity is graduated or measured: for the affinity still exists whether the attraction be taking place or not. Hence where the attraction is strong, we assert the affinity to be close; where it is weak we assert it to be remote. Yet in common language the terms are often used convertibly; and chemical or elective attraction, and chemical or elective affinity are often employed, though not always with strict propriety, to explain each other. While the attraction of the philosopher takes place between masses situated at a greater or less distance from each other, the affinity of which we have been treating operates only upon heterogeneous particles at imperceptible distances, or in the vicinity of contact. A general idea of this affinity may be obtained from the following experiment: Common salt, when thrown into pure water, melts, and very soon diffuses itself through the whole of the liquid, as may be known by the taste. The salt is now combined with the water, and cannot be separated by filtration or any mechanical means; but if a quantity of spirit of wine be poured into the solution, the whole of the salt immediately fails to the bottom. The particles of the salt unite with those of the water in consequence of the attraction or affinity which subsists between them: spirit of wine has also an affinity for water, much stronger than salt has; and it is in consequence of this superior affinity that the water leaves the salt to unite with the spirit of wine, and the salt, being unsupported, necessarily falls by its gravity. All substances which are capable of combining together, are said to have an affinity for each other: those, on the contrary, which do not unite, are said to have no affinity for each other. The first of these may be instanced in the above experiment; and the last, in water and oil, which, having no mutual ailinity, cannot be made to combine. It appears also, that substances differ in the degree of their affinity for other substances; since, in our experiment, the spirit of wine displaced the salt and united with the water, and consequently has a stronger affinity for water than salt has. As this athinity is the great agent in all the operations of nature and art, that are referable to the science of chemistry, a consideration of its nature is an object of the utmost importance. While its laws are unknown, chemistry is not a science, but a wilderness of facts, without beauty, without order, and almost without utility. It is the knowledge of allinity which guides us in our investigation of the phænomena of nature, which shews us their order, and points out their mutual dependence, and which enables us to direct them as we think proper, to make them subservient to the improvement of the arts, and thus to render then the ministers of our comforts and enjoyments. The general principles, or laws, which are observed in the operations of this power, are the following: 1. It takes place between the constituent or integrant particles of bodies of different natures; for when two bodies are united by affinity, how small a portion soever of the compound we examine, we shall always find it to contain both of the ingredients; and the bodies must be of different natures, otherwise the only power that would be exerted is that of cohesion, or, as it is called, the affinity of aggregation. 2. Its efficacy is in the inverse ratio of the affinity of aggrega tion; for, as it is the latter power which combines the integrant and homogeneous particles, and holds them together, it so far hinders them from separating in order to join the parts of another body, and therefore the greater this force is, the less efficacious is the affinity of composition, and vice versa. 3. When two or more bodies are united by this affinity, they suffer a change of temperature at the instant of their union. This change depends upon that produced in the degree of attraction for the natter of heat, which is sometimes disengaged in the process, and sometimes absorbed. 4. The compound possesses properties different from those which each of the bodies possessed before their union. This difference takes place, not only in the taste, but also in the smell, colour, form, consistency, and fusibility of the compound. Instances are constantly occurring in chemical operations in proof of this law. 5. Bodies have not all the same degree of chemical attraction with regard to one another; but each body has its peculiar degree of atlinity for other bodies. This law, which must have been observed as early as chemical phenomena were noticed, is abundantly confirmed by constant experience. 6. That bodies may unite chemically, it is, in general, necessary that one of them, at least, be in a fluid state; not that of gaseous or elasi fluidity, which is very unfavourable to combination, but the liquid or non-clastic state, whether by fusion or solution. The union in this case depends not on any superior power possessed by that body which is termed the solvent, but results from the reciprocal action of the molecule of the two bodies on each other. Although every chemical combination is produced by the operation of the same gene ral principle, modified and directed by circumstances, yet as the phenomena vary considerably in different cases, it has been found expedient, for the sake of perspicuity, to divide them into classes, and to distinguish the various modes in which affinity operates by differ ent names. Thus we have concurrent affinity, simple and compound affinity, disposing, quiescent, divellent, resulting affinity, &c. all which will be explained as we proceed, when the various phænomena, necessary to illustrate the subject, will present themselves. All the known instances of affinity may be arranged under the three first classes; though some chemists, and perhaps with propriety, have taken in also the fourth for this purpose. I. Concurrent affinity is that by which two or more substances are united into one homogeneous body. When two bodies are employed it is evident that, if the force of their mut affinity is ever so little greater than the sum of their respective degrees of cohesion, combination will take place: thus, if a piece of quick lime be put into muriatic acid, the two substances will unite and form an homogeneous compound, called muriat of lime, possessing properties which differ both from those of the lime, and those of the acid. That this rule may be extended to more than two substances, will appear on mixing together sulphuric acid, alumine, and potash, the concurrent affinities being greater than the force of cohesion, the substances will unite and form common alum, a salt possessing peculiar properties, which could not be inferred from those of its elements. II. Simple affinity, or single elective attraction, is that by which a body, compounded of two substances, is decomposed on the approach of a third substance, having a greater affinity for one or both the other substances than they have for each other; and by which a new combination is produced, and a new substance is formed. Thus when a metal is dissolved by an acid, and kept in union with it by a certain degree of elective attraction, it an alkali be presented to this compound, a decomposition takes place, the alkali unites with the acid by virtue of a superior degree of athinity, and forms a new compound, while the metal is precipitated. Of the same kind is the experiment related in the beginning of this article. So also, when the sulphuric acid is combined with magnesia, forming with it the salt called sulphat of magnesia, as soon as potash is presented, the acid leaves the magnesia, which is precipitated, and unites with the potash. The following is an instance in which two combinations take place by simple affinity. When some potash is dropped into tartarous acid, part of the acid unites with the al kali, and forms tartarite of potash; after this the remainder of the acid combines with the tartarite just formed, and composes a new salt known by the name of acidulous tartarite of potash, or tartar. Strictly speaking, this is rather a case in which the concurrent is succeeded by the elective affinity.-In the beginning of the last century, viz. about the year 1718, Geoffroy invented a method of representing the different degrees of affinities, which he called tables of affinity. His method consisted in placing each of the substances whose affinities he wished to express at the top of a column, and the substances with which it united in the same column below it, in the order of their respective affinities. According to this method, the affinity of water for spirit of wine and for common salt would be marked thus: WATER. Spirit of wine. Common salt. found not to be acted upon by the body at the head of the column. Rudiger in 1756 gave a table of affinity reduced to 15 columns. M. Limbourg, in 1758, extended the number of columns to 33, and otherwise much improved the tables. From this period, the importance of the subject being fully established, tables were multiplied, and the general system of affinity was investigated by the most able chemists. At length, in 1775, the illustrious Bergman published his dissertation on elective attractions, and successive editions of his tables made their appearance in 1779 and 1783. In these tables, which do honour to the skill and industry of their author, the affinities of no less than 50 substances are clearly ascertained, and the distinction made between those that take place in the moist and in the dry way. His method of registering cases of compound affinity, will be noticed when we come to that part of our subject. The following tables are improved and enlarged from Bergman's by Dr. Pearson, and corrected by the latest discoveries. Their utility is almost unspeakable, for they enable us to discover any particular fact we are enquiring after, as far as simple affinity is concerned, and to compare and foretel, by inspection, the results of a great variety of processes and experiments. SIMPLE ELECTIVE AFFINITIES. In Water, or by Solution. This method has been universally adopted by cceeding chemists, and has contributed very mach to the advancement of the science. Geoffroy's table consisted of 17 columns; and in 1750 Gellert published a new table extendeto 28 columns, at the bottom of each of vira was a list of substances which he had TABLE I. |