promptly and decisively on the primæ viæ, without, however, producing any griping, or leaving languor or faintness after its operation. CHEMICAL AFFINITY. (See Chemistry.) CHEMISTRY. By this name, the etymology of which is uncertain, we understand the science which teaches the nature of bodies, or rather the mutual agencies of the elements of which they are composed, with a view to determine the nature, proportions and mode of combination of these elements in all bodies. Natural philosophy, or physics, examines the reciprocal influence of matter in masses. Chemistry treats of the mutual action of the integrant parts. In the former, the phenomena are produced by the general attraction or repulsion of bodies; in the latter, by minute combination or decomposition. With our present knowledge of matter and its laws, we cannot separate physics entirely from chemistry: one science cannot be studied without the other. Those artisans who first discovered the means of melting, combining and moulding the metals; those physicians who first extracted vegetable substances from plants, and observed their properties, were the first chemists. Instead, however, of observing a philosopha ical method in their examinations; instead of passing from what was known to what was unknown, early inquirers suffered themselves to be led astray by astrological dreams, the fables of the philosopher's stone, and a hundred other absurdities. (See Alchemy.) Until the year 1650, we find little worthy of notice in the history of chemistry. Rhazis, Roger Bacon, Arnaud de Villeneuve, Basilius Valentin, Paracelsus, Agricola, &c., observed some of the properties of iron, quicksilver, antimony, ammoniac, saltpetre. They discovered sulphuric, nitric and other acids; the mode of rectifying spirits, preparing opium, jalap, &c., and of purifying the alkalies. Glauber was distinguished for the accuracy of his observations. He endeavored to improve certain instruments; advised operators not to throw away any residuum, in performing experiments, as useless; discovered the salt which is called, from him, Glauber's salt, &c. Such isolated discoveries, however, could not form a complete science. Stahl appeared, and, although his theory was unsatisfactory and entirely gratuitous, and, as later observations have proved, erroneous, yet he laid the foundations of a regular science. He was himself much indebted to the celebrated Becher, whose views he corrected and extended. He was sensible that the greater part of chemical phenomena might depend on a general cause, or, at least, on a few general principles, to which all combinations must necessarily be referred. He supposed that bodies contained a combustible element, which inflammable bodies lost by being burned, and which they could regain from other more inflammable bodies. This element he called phlogiston. The establishing of a hypothesis, which connected almost all phenomena with each other, was an important step. Boerhaave adopted Stahl's system, and contributed much to its general diffusion. He is the founder of philosophical chemistry, which he enriched with numerous experiments, in regard to fire, the caloric of light, &c. Although the principles on which those philosophers proceeded were false, yet the science was much advanced by their labors. It was reserved for Black, Priestley, Cavendish and Lavoisier to overturn Stahl's system, and substitute the pneumatic or antiphlogistic chemistry, the best history of which is to be found in Fourcroy's Philosophie Chimique, and his Système des Connaissances Chimiques. As soon as the composition of the atmospheric air was known, it was observed that combustible bodies, burning in contact with it, instead of losing one of their elements, absorbed one of the component parts of the air, and were thus increased in weight. This component part has received the name of oxygen, because many of the combustible bodies are changed by its absorption into acids. Oxygen now took the place of phlogiston, and explained the difficulties which beset the phlogistic theory. Light and unity were introduced into chemistry by the new technical nomenclature adopted in 1787, by the aid of which all the individual facts are easily retained in the memory, since the name of each body is expressive either of its composition or of its characteristic property. 12 or 15 terms have been found sufficient for creating a methodical language, in which there is no inexpressive term, and which, by changing the final syllables of certain names, indicates the change which takes place in the composition of the bodies. Lavoisier, Fourcroy, Guyton de Morveau and Berthollet were the authors of this felicitous innovation. The chemical terminology admits of nothing arbitrary, and is adapted not only to express known phenomena, but also any which may be hereafter discovered. It is the first example of a systematic and analytic language. The commencement of the 19th cen tury forms a brilliant era in the progress of chemistry. The galvanic apparatus of Volta presented to the experimenter an agent unequalled in the variety, extent and energy of its action upon common matter. With this apparatus, sir Humphrey Davy commenced a series of researches, which resulted in a greater modification of the science than it had ever before experienced. He proved that the fixed alkalies were compounds of oxygen with metallic bases, and thus led the way to the discovery of an analogous constitution in the alkaline earths. To the same individual the science is principally indebted for the establishment of the simple nature of chlorine, and for the investigation of iodine. His researches concerning the nature of flame, resulting as they did in the invention of the miner's safety-lamp, afforded to mankind a new demonstration of the utility of philosophy in contributing to the improvement of the arts of life. But that department of chemistry, which has of late been most successfully investigated, relates to the definite proportions in which bodies unite to form the various chemical compounds. To establish the conclusions which have been arrived at, a multitude of exact analyses were requisite. These were accomplished principally through the labors of Vauquelin, Gay-Lussac, Thénard, Berzelius and Thompson; and have terminated in the establishment of the general truth, that, when bodies combine chemically and intimately with each other, they combine in determinate quantities; and that, when one body unites with another in more than one proportion, the ratio of the increase may be expressed by some simple multiple of the first proportion. Upon this general fact, doctor Wollaston constructed the logametric scale of chemical equivalents an invention which has contributed, in an eminent degree, to render our knowledge of the constitution of compounds precise, by introducing the sure basis of arithmetical relations, which, when fixed with accuracy, are not susceptible of change. The doctrine of definite proportions may, therefore, be regarded as having communicated to the principles of chemistry that certainty which has long been considered as peculiar to the mathematical sciences; and it is in the developement of these important relations that the advancement of the science has been most conspicuous.-Among the still more recent improvements in chemistry may be cited the discovery of Döbereiner, relating to the power of platinum in effecting the combination of ox ygen and hydrogen; the researches of Faraday, in which many of the gases have been reduced to the liquid form; the discovery of new compounds of carbon and hydrogen, and the singular fact, which they exhibit, of different combinations being established in the same proportions; the elucidation of the new compounds of chlorine with carbon; of the peroxide of chlorine; the hydriodide of carbon; the perchloric, iodous, fulminic, and other, acids; the discovery of the real bases of silex and zircon, and that of the new principle, brome: add to these, that our knowledge of light and electricity has been greatly enlarged, and that the phenomena of electro-magnetism are altogether new, and it becomes striking strikingly obvious that chemistry is still a progressive science. "Nor can any limits be placed to the extent of its investigations. Its analysis is indefinite; its termination will have been attained only when the real elements of bodies shall have been detected, and all their modifications traced: but how remote this may be from its present state we cannot judge. Nor can we, from our present knowledge, form any just conception of the stages of discovery through which it has yet to pass." Chemistry has two ways of becoming acquainted with the internal structure of bodies, analysis and synthesis (decomposition and combination). By the former, it separates the component parts of a compound body; by the latter, it combines the separated elements, so as to form anew the decomposed body, and to prove the correctness of the former process. These methods depend on a complete knowledge of the two powers, by which all bodies in nature are set in motion, viz., attraction and repulsion. Attempts have been made to distinguish the attraction of elementary particles from planetary attraction; the former being designated as chemical affinity: but nature has only one kind of attraction. The alternate play of attraction and repulsion produces a great number of sensible phenomena, and a multitude of combinations, which change the nature and the properties of bodies. The study of these phenomena, and the knowledge of these combinations, appertain to the department of chemistry. The history of a body must always precede its analysis. The mere examination of its form, its color, its weight, and the place where it was found, &c., is often sufficient, by a comparison, to lead to a knowledge of its chemical properties. There is no science more extensive than chemistry, nor is it possible for one person to embrace it in its the same all the whole extent. To facilitate the study, it is considered in different points of view, and thrown into divisions and subdivisions, so that a person may devote himself to one department of it, although the method of observing, analyzing and combining is in all, and although all t phenomena must be explained by the general theory, and refer to certain laws, of which a previous knowledge is requisite. These laws constitute what is called philosophical chemistry, which explains what is meant by the affinity of aggregation or cohesion, and by the affinity of composition, or chemical affinity. It treats of the phenomena of solution, saturation, crystallization, ebullition, fusion, neutralization, Chemical processes, by changing or modifying the properties of bodies, suggest to the observer important considerations on the changes of form, density and temperature. Philosophical chemistry weighs these considerations. It shows, further, that affinity may be exerted, 1. between two simple bodies; 2. between a simple and a compound one; 3. between compound bodies; and, establishing the principle, that the same body has not the same affinity for all others, but attracts them unequally; it shows us the laws which determine this preference, and the circumstances which modify it; such as cohesion, mass, insolubility, elasticity and temperature. It measures the degree of affinity, whether of simple or compound bodies. It observes the circumstances which aid or obstruct the play of attraction, and shows that two bodies will not act upon each other, unless one of them, at least, is in a fluid state; that bodies, even in a state of solution, act upon each other only at imperceptible distances; that two bodies, which have no perceptible affinity, may be made to combine by the interposition of a third; and, finally, that the peculiar properties of bodies are destroyed by their combination, and the compound possesses entirely new properties. Proceeding from these principles to the examination of bodies themselves, philosophical chemistry considers the effects of light, heat and electricity; the nature of the simple and compound inflammable bodies; of air and water; the composition and decomposition of acids; the nature and properties of the salts; their relations to the acids; the calcination, solution and alloying of metals; the composition and nature of plants; the characteristics of the immediate elements of vegetable substances; the phenomena of animalization; the properties of animal compounds, and the decay of organic substances. This is the sphere of philosophical chemistry, while it confines itself to general views. According to the application of these general views, chemistry is divided into seven or eight branches, which we have yet briefly to survey. The study of the great phenomena which are observed in the atmosphere, and which are called meteors, constitutes meteorological chemistry. This explains the formation of the clouds, rain, mist, snow, waterspouts; the state of the atmosphere in relation to the hygrometer, barometer and thermometer; the nature of the aurora borealis, meteoric stones; in short, all the chemical processes going on above the surface of the earth. Geological chemistry treats principally of the great combinations of nature, which produce volcanoes, veins of metals, beds of mineral coal, basalt, mineral waters, the enormous masses of salt and lime, the saltpetre in the bed of the Indus, the natron of the lakes of Egypt, the borax of the lakes of Thibet. The geological chemist endeav ors to discover and explain the causes of deluges, earthquakes, the decrease of the waters on the globe, the influence of climate on the color of animals and plants, on the smell of flowers, and the taste of fruits. In these general views, he needs the aid of natural philosophy and physics. Chemistry, in its application to natural history, is divided in the same manner. There is a chemistry of the mineral kingdom, which comprises metallurgy and assaying, and the examination of all inorganic substances, as stones, salts, metals, bitumen, waters; a chemistry of the vegetable kingdom, which analyzes plants and their immediate products; and a chemistry of the animal kingdom, which studies all substances derived from living or dead animals. This last is subdivided into physiological chemistry, which considers the changes produced in animal substances by the operation of life; pathological chemistry, which traces the changes produced by disease or organic defects; therapeutic or pharmaceutic chemistry, which teaches the nature and preparation of medicines, shows the means of preserving them, and exposes the pretensions of empirics; hygietic chemistry, which acquaints us with the means of constructing and arranging our habitations, so as to render them healthy, of examining the air which we must breathe in them, guarding against contagious diseases, choosing wholesome food, discovering the influence of occupation, fashion and custom on the health. Agricultural chemistry treats of the nature of plants and soils, and the laws of production. Sir Humphrey Davy first gave it the character of a science. It treats, 1. of the general powers of matter which have any influence on vegetation, of gravity, cohesion, chemical affinity, heat, light, electricity, the elements of matter, especially such as are found in vegetables, and the laws of their composition and arrangement; 2. of the organization of plants, their structure, the chemical composition of their organs, and the substances found in them, &c.; 3. of soils; 4. of the nature of manure.-Chemistry, finally, exerts an influence on the routine of domestic life, and on the arts. It simplifies and regulates the daily offices of the housekeeper; renders our dwellings healthy, warm, light; assists us in preparing clothing, food, drink, &c.: it teaches the best way of making bread; preparing and purifying oils; of constructing bakehouses, ovens and hearths; of bleaching and washing all kinds of stuff; of producing artificial cold, &c. The application of chemistry to the arts and manufactures is, however, still more important and extensive. Here its aim is to discover, improve, extend, perfect and simplify the processes by which the objects to be prepared may be adapted to our wants. We close our remarks with the observation, that a knowledge of chemistry may frequently be useful in judicial proceedings, in exposing crime; e. g., in cases of poisoning, counterfeiting coins and written documents, &c. Chemical Classification and Nomenclature. The chemist finds a small number of bodies, from which only one kind of matter can be obtained, in the present state of his knowledge, and by the instruments and agents which he now has at his disposal. On the other hand, there is a large number of bodies, from which he obtains several kinds of matter. The former he calls elements, or simple bodies; the latter, compound bodies. The number of simple bodies now known is 53: that of the compounds is much greater, and might, at first, appear to be infinite, since not only a difference of elements, but even a difference of the proportions in which they are combined, ed, makes an essential difference in the properties of the compound. It is, however, much less than would be supposed, and even less than the number of possible combinations of simple bodies. Twelve of the simple bodies are oxygen, iodine, chlorine, bromine, fluorine, hydrogen, boron, carbon, phosphorus, sulphur, azote and selenium; and 41 are metals. (q. v.) The five first are called supporters combustion, because they combine with the others, producing a disengagement of heat and light, and acidifying principles, because they are also capable of producing acids by a similar combination. The 48 others are called simple combustibles, because their union with the supporters of combustion, abovementioned, is a real combustion. Compound bodies, as has been observed, are not so numerous as might be supposed. They result, 1. from the combination of oxygen, or one of the other simple supporters of combustion, with one of the simple combustibles; such are the acids: 2. from that of a simple body combined with oxygen, with another similar compound; such are the salts: 3. from that of two, three, rarely four, simple combustibles with one another: 4. from that of oxygen with hydrogen and carbon, forming vegetable matter: 5. from that of oxygen with hydrogen, carbon and azote, forming animal matter. Combustibles combined with the simple supporters of combustion are sometimes called burned bodies; from the number of their elements, they are also called binary compounds. When their taste is acid, and they have the property of reddening vegetable blues, they are termed acids. If they are not acid to the taste, and have the property of turning blue what has been reddened by acids, they are distinguished by the termination ide, as oxide, chloride, &c. If only one of the latter class is formed, that is, if the supporter of combustion will unite with the combustible in only one proportion, we call this compound simply the oxide, chloride, &c., of the combustibles; as, oride ide of carbon. If they unite in several proportions, we call the first, or that which contains the smallest proportion of oxygen, &c., protoxide, &c.; the second, deutoxide; the third, tritoxide. The highest is also called peroxide. So, if only one acid is formed, we designate it by the name of the combustible, with the termination ic. Thus carbon with oxygen forms carbonic acid. If several are formed, that which contains the larger proportion of the acidifying principle is designated by the termination ic, that which contains less, by the termination ous. Thus sulphur forms sulphuric acid and sulphurous acid. If there are still intermediate compounds, we annex hypo (signifying less), to designate a lower degree of acidity. Thus we should have sulphuric, hyposulphuric; sulphurous, hyposulphurous. In the acids and oxides, chlorides, &c., the combustible is called the base. When the base is the same, the peroxide, &c., always contains less oxygen, &c., than the lowest acid. For the names of compounds of two binary burnt bodies, no rules have been adopted to express the union of two oxides, two acids, or an acid with a nonmetallic oxide. But those formed of acids and metallic oxides are called salts, and their individual names are formed by changing the termination of the acid and placing it before the name of the metal; the termination ous is changed into ite, and ic into ate; sulphurous acid with the oxide of tin would form sulphite of tin; sulphuric acid and tin, sulphate of tin. If the same acid combines with more than one oxide of the same metal, then we prefix the characteristic of the oxide to the name of the acid; thus sulphuric acid, combined with the protoxide of iron, forms the protosulphate, with the peroxide, the persulphate, of iron. Other substances have also the property of uniting with acids, neutralizing them, and forming compounds analogous to salts. There are no general rules for the names of these compounds; but the substances themselves are called salifiable bases. The rules of nomenclature, in regard to the combination of the combustibles, vary:1. If the constituents are metals, they form alloys. 2. If the compounds are solid or liquid, and formed of a metallic and a non-metallic combustible, we give to the latter the termination uret; as, carbon with iron forms carburet of iron. If both are non-metallic, the termination uret may be attached to either; as, phosphuret of sulphur, or sulphuret of phosphorus. 3. If the compound is gaseous, we name the gas, or one of the gases, if it is composed of two, and join the other component as an adjective; as, phosphureted hydrogen. CHEMNITZ, the principal manufacturing town in the kingdom of Saxony, in the department of the Erzgebirge, on the river Chemnitz, is well built, and contains 1000 houses, with 16,000 inhabitants, amongst whom are 1197 master-weavers, and 860 journeymen and apprentices. The principal manufactures are white and printed calicoes, ginghams, handkerchiefs, and various articles used for bed-quilts. Of 12 cotton factories, founded about the middle of the last century, several employ from 300 to 500 workmen. 40 spinningmills, in the town and its environs, manufacture upwards of 1,000,000 pounds of yarn annually. The manufacture of cotton hose has been brought to very great perfection, and they are exported in large quantities to the U. States and South America, besides furnishing most of the European markets, through the fairs of Leipsic, Frankfort and Brunswick. Within a few years, they have even been sent to England, strange as this may sound. They are manufactured in the neighboring villages. CHEMNITZ, Martin, a distinguished Protestant theologian of the 16th century, rose, by his extraordinary talents and profound knowledge, from low circumstances to a high degree of celebrity. He was born at Treuenbrietzen, in the Mark of Brandenburg, Nov. 9, 1522, of poor parents; received his education at Magdeburg and Frankfort on the Oder, and, in 1544, became a schoolmaster in Writzen on the Oder, to obtain the means of continuing his studies at Wittenberg. By the advice of Melancthon, he applied himself to mathematics and astrology. In 1550, he became librarian of duke Albert of Prussia. He then wrote his Loci theologici (edit. Polycarp. Leyser, Frankfort on the Maine, 1591, fol.), a valuable commentary on Melancthon's system of dogmatics. Being invited to Brunswick, as minister, he attacked the Jesuits in his Theologiæ Jesuitarum præcipua Capita (Leipsic, 1562), and, when the council of Trent thought itself assailed in this work, he wrote his Examen Concilii Tridentini (best edit. 1707, fol., Frankfort on the Maine), a work of great historical value. He adhered to Luther's doctrine concerning the eucharist, wrote on this subject, composed the Corpus Doctrinæ prutenicæ for the Lutherans, and gradually became so implicitly attached to the Lutheran doctrine, that his efforts in support of it contributed to check the progress of theological science. He died, April 8, 1586, at Brunswick. He was the author of a great number of works besides those already mentioned.-His grandson, Philip Bogislav von Chemnitz, born in 1605, a soldier in the Swedish service, wrote the celebrated work, De Ratione Status in Imperio nostro Romano-Germanico, &c. auct. Hippolito a Lapide (1640, 4to., and 1647, 12mo.), which did more injury to the interests of the emperor than the loss of many battles. He then became Swedish historiographer, and wrote a history of the Swedish and German war (1648 and 1653). He died at his estate near Hallstadt, in Sweden, in 1678. CHÉNIER, Marie Joseph de, born, Aug. 28, 1764, in Constantinople (where his father, Louis Chénier, known as the author of valuable works on the Moors, |