land, at present merely nominal. It's province is stated to be, the enactment of canon-law, subject to the licence of the king; and the examination and censuring of all heretical and schismatical books and persons; but from its judicial proceedings lies an appeal to the king in chancery, or his delegates. In 1665, the convocation then assembled surrendered to parliament the right of taxing the clergy; and ecclesiastical persons in return obtained the right of voting at elections: since which alteration, the convocation has usually been called and dissolved together with the parliaments ; but rogued from time to time through the whole period proof its existence.

COOPER, a maker of casks. This hard-working business has several branches. Some casks are tight, for holding liquids, and others not so, for dry goods, package, and soap. The making of soap-casks is the lightest labour, and requires the least capital; that of small light casks is more laborious, and demands a larger fund; that of butts, hogsheads, and large vessels for brewing and other extensive purposes, stands, in both respects, the highest in the

scale.

COPAL, improperly called gum-copal, a gum of the resinous kind, the concrete juice of a tree called rhus copallinum, which grows in New-Spain. It is dissolved in linseed-oil by digestion, with a heat very little less than sufficient to boil or decompose the oil; and the solution, diluted with spirit of turpentine, forms a well-known, transparent varnish.

COPERNICAN system, See SOLAR system.

COPHTI, or copts, a name given to the jucobites, a

sect of christians in Egypt. The principal errors in regard to doctrine, of which they are accused by the Roman church, are, 1. The acknowledgement of seven sacraments. 2. The denial of the proceeding of the Holy-Spirit from the Son; 3. The allowance of three general councils of the church; 4. The allowance of one nature, will, and operation in Jesus Christ, after the union of the humanity with the godhead. In point of discipline, they ordain deacons of five years of age; and allow marriage in the second degree of affinity. The churchgovernment of the jacobites is episcopal; and the sect appears to differ but little from the Greekchurch; it has, however, a patriarch of its own. The other christians of Egypt are called melchites.

COPPER, the finest of the imperfect metals. It has obtained the name Venus, on account of its rea diness to unite with several metallic substances. Native copper is found in Sumatra, it is picked up in loose masses, on the hills shattered by earthquakes, which are very prevalent in that island. The natives are ignorant of mining; but Mr. Macdonald supposes that its mountains contain inexhaustible stores of this mineral. On smelting it, a considerable portion of gold is found to be included in the ore. Paris-mountain, in the isle of Anglesea, is famous for its copper-works. A method of obtaining fine copper from springs that, according to common expression, turn iron into that metal, has been known for centuries in Germany, and, within these few years, practised in the united kingdom. The explanation of this circumstance is, that the iron is dissolved by the vitriolic acid of the springs in question, and the copper precipitated in

its metallic form in place of the iron. The present bishop of Llandaff relates that at the copper-mines at Arklow, in Ireland, one of the workmen having left an iron shovel in a stream that issues from the works, he found it, after having lain there some weeks, so incrusted with a coat of copper, that it was at first believed to be changed into that metal. The proprietors of the mines, in pursuance of the hint, made proper pits and receptacles for the water, and obtained, by means of soft iron bars put into them, such quantities of copper that the streams are now of equal value with the mines themselves. One ton of iron produces nearly two tons of coppermud; and each ton of mud, when melted, sixteen hundred weight of copper: and the metal thus obtained sells for £10 a ton more than that fluxed from the ore. The lessees of the Paris mines, annually raise from six to seven thousand tons of saleable ore, and daily employ forty furnaces in smelting it. This ore contains a large proportion of sulphur, which must be separated by roasting, before it can be melted, or, technically speaking, fluxed. The inflammable chemical liquor, with part of the vitriolic acid it contains, are dispersed in the air by the force of the fire; while another part of the acid attacks and dissolves so much of the copper, that the water in which the roasted ore is washed, has yielded, in one year, iron being immersed, an hundred tons of fine copper. Copper is injurious to the animal system. See POISON.

COPPER-plate. See ENGRAVING.

COPPER-plate, printing. See PRINTING,

COPPERAS, is the sulphate of iron, and is common. ly called green vitriol. If sulphuric acid be diluted

with water, and be poured upon iron, much effervescence will be seen; the metal will be dissolved, and the solution, when evaporated, will exhibit the sulphate of iron, or common copperas, which is a neutral salt in a very impure state. Copperas 'is the basis of many dyes: it gives a fine black, though it rather subjects the material to decay, unless used with extreme caution, the least excess occasioning the cloth, &c. to rot very soon. It seems that wool is more affected by it than felt, as is obvious from the greater duration of hats beyond what broad cloths, &c. exhibit when dyed black. Ink owes its rich blackness principally to the copperas which it contains; and our fine black leathers are equally indebted to its powerful qualities, that so firmly fix the colour on all occasions. Many servants are in the habit of cleansing their copper kitchen-utensils with green vitriol, which is extremely dangerous: the copperas is highly corro. sive, and disengages a very large portion of the copper, which cannot be always removed, even when much pains are taken, the salt being buried under projecting rims, rives, &c. We are apt to believe that many most painful and dangerous complaints have resulted from this, though probably they may have been assigned to other supposed

causes.

Copy-hold, a sort of tenure of landed property, according to the custom of the manor, the holder of which is subject to certain services and fines, and has no other authority for his possession than the copy of the court-roll made by the steward of the lord's court. A copy-hold is taken either in fee

simple, fee-tail, for life, years, or at will; but generally in fee or for three lives.

CORAL, of corallina, a marine production, concerning which it is by no means agreed whether it be animal or vegetable. The species are several, distinguished by the form of their branches; and they are found adhering to shells, rocks, &c. Mr. Macdonald, in a paper on the coral of Sumatra, in the fourth volume of the Asiatic Researches, after referring that species of plant, as he denominates it, to the class of Cryptogamia of Linnæus, observes, that it differs from the descriptions of coral hitherto given, and, therefore, obliges us with the following account of it: "It is of three colours; red, black, and whitish-yellow; the last is the most common in the eastern seas. It is of a fungous texture, equally hard in and out of its natural element; and its pores are charged with a juice of a milky appearance, in some degree acrid. The bark covers every part of the tree, and contains a number of perforated papillæ, or pores, terminating in tubes. The internal projections of the papillæ adhere to the particles of sand and stone, on which the coral grows, and are the only appearance of roots it exhibits." The tree, in general, he observes, grows to the height of two feet, but in some instances to that of ten. From its rapid growth on the western coast of Sumatra, he thinks that the coral ought undoubtedly to rank as a vegetable: yet modern naturalists seem to have determined differently concerning this production of the ocean; some affirming it to be a fossil, formed like crystals and spars, while others rank it among the animal tribes. Sir