eety of fellows, who, upon St. Andrew's day, if it falls on a Thursday, if not, on the first Thursday after, elect seven counsel lors, who chuse the president and the other officers for the ensuing year. By their charter, the president and censors have power to convene before them all persons that presume to practise physic within the city of Edinburgh, or the liberties thereof, without the license of the College; and to fine them in five pounds sterling. They are also impowered to visit apothecaries' shops, and examine apothecaries themselves; with several other rights and privileges.

COLLEGE Sion, or the College of the London clergy, was formerly a religious house, next to a spittal, or hospital, and now it is a composition of both, viz. a college for the clergy of London, who were incorporated in 1631, at the request of Dr. White, under the name of the president and fellows of Sion College; and an hospital for ten poor men, the first within the gates of the house, and the latter without. This College consists of a president, two deans, and four assistants, who are annually chosen from among the rectors and vicars in London, subject to the visitation of the bishop. They have one of the finest libraries in England, built and stock. ed by Mr. Simpson, chiefly for the clergy of the city, without excluding other students on certain terms; they have also a hall with chambers for the students, generally filled with the ministers of the neighbouring parishes.

COLLEGE, Gresham, or COLLEGE of philosophy, a College founded by Sir Thomas Gresham, who built the Royal Exchange, a moiety of the revenue whereof he gave in trust to the Mayor and Commonalty of London, and their sucessors for ever, and the other moiety to the Company of Mercers; the first, to find four able persons to read in the College, divinity, astronomy, music, and geometry; and the last, three or more able men to read rhetoric, civil law, and physic; a lecture upon each subject is to be read in termtime, every day, except Sundays, in Latin, in the forenoon, and the same in English in the afternoon: only the music lecture is to be read alone in English.

COLLEGE of Heralds, or COLLEGE of Arms, commonly called the Heralds Of fice, a corporation founded by charter of King Richard III. who granted them several privileges, as, to be free from subsidies, tolls, offices, &c. They had a second charter from King Edward VI.; and a house built near Doctors' Commons by

the Earl of Derby, in the reign of King Henry VII. was given them by the Duke of Norfolk, in the reign of Queen Mary, which house is now rebuilt. This College is subordinate to the Earl Marshal of England. They are assistants to him in his court of chivalry, usually held in the common hall of the College, where they sit in their rich coats of his Majesty's arms.

COLLEGE of Heralds, in Scotland. The principal person in the Scottish Court of Honour, is Lyon King at Arms, who has six heralds and six pursuivants, and a great number of messengers at arms under him, who, together, make up the College of Heralds. The Lyon is obliged to hold two peremptory courts in the year, at Edinburgh, on the 6th of May and the 6th of November, and to call officers of arms and their cautioners before him upon complaints; and, if found culpable upon trial, to deprive and fine them and their cautioners. Lyon and his brethren, the heralds, have power to visit the arms of noblemen and gentlemen, and to distinguish them with differences, to register them in their books, as also to inhibit such to bear arms, as by the law of arms ought not to bear them, under the pain of escheating to the King the thing whereon the arms are found, and of a hundred marks Scots to Lyon and his brethren; or of imprisonment during Lyon's pleasure. The College of Heralds are the judges of the malversation of messengers, whose business is to execute summonses and letters of diligence for civil debt, real or personal.

COLLEGE of Cardinals, sometimes called the Sacred College, a body composed of the three orders of Cardinals.

COLLETIA, in botany, a genus of the Pentandria Monogynia class and order. Corolla campanulate, furnished with five scale-like folds; calyx none; fruit three grained. One species, found in the Brazils.

COLLIERS, vessels employed to carry coals from one port to another, principally from the northern parts of England to the capital, and more southern parts, and foreign markets. Their trade is known to be an excellent nursery for seamen.

COLLINSONIA, in botany, a genus of the Diandria Monogynia class and order. Leaves ovate, glabrous; stem glabrous. Two species, found in North America.

COLLYRIUM, in pharmacy, a topical remedy for disorders of the eyes.

COLOGNE earth, a substance used in painting, much approaching to amber in its structure, and of a deep brown. It has

generally been esteemed a genuine earth, but has been discovered to contain a great deal of vegetable matter, and, indeed, is a very singular substance. It is dug in Germany and France: the quantities consumed in painting in London are brought from Cologne, where it is found very plentifully; but our own kingdom is not without it, it being found near Birmingham, and on the Mendip-hill, in Somersetshire; but what has been yet found there is not so pure or fine as that imported from Cologne.

COLON, the second of the three large intestines, called intestina crassa. See ANATOMY.

COLON, in grammar, a point or character marked thus (:), shewing the preceding sentence to be perfect or entire; only that some remark, farther illustration, or other matter connected therewith, is subjoined. See POINTING, PERIOD, COMMA, &c.

COLONEL, in military matters, the commander in chief of a regiment, whether horse, foot, or dragoons.

COLONEL, lieutenant, the second officer in a regiment, who is at the head of the captains, and commands in the absence of the colonel.

COLONNADE, a range of insulated

columns. See ARCHITECTURE.

COLONY A colony is a settlement formed by the inhabitants of any nation, in some part of the world unoccupied by any other civilized nation. The motives for forming them have been vari

ous.

In colonies there is generally abundance of good land; hence the necessaries of life are usually to be had in plenty, by any one who will take the trouble ne. cessary to produce them; and, consequently, population usually has a tendency to increase with great rapidity. The inhabitants of some parts of the United States are said to have doubled in fifteen years, at the time those countries were colonies of Great Britain.

The policy of the mother countries with regard to colonies has usually been intended to make the colonists buy the goods of the mother country as dear as possible, and sell their own productions as cheaply as possible.

Hence the trade of colonies usually has been confined, by strict commercial laws, wholly to the mother country.

The consequence of these regulations has probably been, that in the colonial trade the merchants and manufacturers have sold their goods dearer, and bought

colonial produce cheaper, than they other wise might have done, though even this may be doubted; but most certainly the inhabitants of the colony have bought dearer, and sold cheaper, than they other. wise would. The prosperity of the colony therefore has been impeded; their progress towards opulence has been less rapid than it would have been under other circumstances; and the mother country has always had a poorer and smaller mar ket for her commodities than she otherwise would have had. The profits per cent. have been perhaps greater, but the whole amount of profit derived from the colony trade has most certainly been less

COLORIFIC earths, in mineralogy, a class or tribe of earths, in the arrangement of Kirwan, described by him as strongly staining the fingers. Of these he enumerates four families, viz. red, yellow, black, and green; the red is the reddle, of dark cochineal red colour, or intermediate between brick and blood red, having neither lustre nor transparency; fracture, earthy, sometimes conchoidal fragments, 1: hardness, 4; sp. gr. inconsiderable; adhering pretty strongly to the tongue; feeling rough; assuming a polish from the nail; diately into powder in water, and not bestrongly staining the fingers; falling immecoming ductile; not effervescing, nor easi ly dissolving in acids. When heated to redness, crackling and growing black; at 159° the specimen melted into a dark gree nish yellow frothy enamel. It differs from red ochres only by containing more argil. The red colour proceeds from oxygena tion, and the absence of acid. The more air of water is expelled by heat, the browner it grows. The yellow is of an ochre yellow colour; as to lustre, externally it often has some gloss, but internally none; it is not transparent; fracture earthy, often inclining to the conchoidal no specific gravity; fragments, inconsiderable; adheres strongly to the tongue; feels smooth, or somewhat greasy; takes a high polish from the nail; strongly stains the fingers; in water it immediately falls to pieces with some hissing; and afterwards to powder, without diffusing itself through it; does not effervesce with acids, nor is easily soluble in them; heated to redness it crackles, hardens, and acquires a red colour, and gives a reddish streak. At 156°, Mr. Kirwan melted a specimen into a liver-brown porous porcelain mass. This yellow earth differs from ochres only in containing a greater proportion of argil; the yellow colour proceeds from the calx of iron, highly oxygenated, and

probably containing both water and acid. Those earths which contain a large proportion of iron have rather an orange colour. According to the analysis of M. Sage of Paris, who has the merit of preserving to his countrymen the immense gains acquired by the Dutch from converting this yellow earth into what is there called "English red," it contains 50 per cent. argil, 40 oxide of iron, 10 of water, acidulated by sulphuric acid. The 3d family, or black; black chalk is of a greyish black colour; fracture imperfectly curved slaty fragments partly flat, partly long splintery; adheres slightly to the tongue, feels smooth, assumes a polish from a knife; gives a black streak, and marks black: in water does not readily moulder, but if taken out cracks in a short time; does not effervesce with acids, nor easily dissolve in them; heated to redness, it crackles and becomes reddish grey, and contains somewhat vitriolic. The 4th family, green earth, is of a greyish green colour; found generally in lumps in the cavities of other stones, or externally investing them fracture, earthy, sometimes uneven,sometimes verging to the conchoidal; sp. gr. 2.637, sometimes feels smooth, does not assume a polish from the knife, nor adhere to the tongue, nor stain the fingers, nor mark while dry, and when wet but lightly in water, it often crumbles after standing about half an hour; does not effervesce with acids, nor is easily soluble in them; heated to redness, it crackles and becomes of a dark reddish cream colour; at 147°, a specimen was melted into a black compact glass, resembling that of basalt; which shews it to consist of silex, argil, iron, not much oxygenated, and oxyde of nickel, from which the green colour is derived, besides water.

COLOSSUS, a statue of enormous or gigantic size. The most eminent of this kind was the colossus of Rhodes, one of the wonders of the world, a brazen statue of Apollo, so high, that ships passed with full sails betwixt its legs. It was the workmanship of Chares, a disciple of Lysippus, who spent twelve years in making it: it was at length overthrown by an earthquake, B. C. 224. after having stood about sixty-six years. Its height was a hundred and five feet: there were few people who could encompass its thumb, which is said to have been a fathom in circumference, and its rngers were larger than most statues. It was hollow, and in its cavities were large stones employed by the artifi

VOL. III.

cer to counterbalance its weight, and render it steady on its pedestal.

On occasion of the damage which the city of Rhodes sustained by the abovementioned earthquake, the inhabitants sent ambassadors to all the princes and states of Greek origin, in order to solicit assistance for repairing it; and they obtained large sums, particularly from the kings of Egypt, Macedon, Syria, Pontus, and Bythinia, which amounted to a sum five times exceeding the damages which they had suffered. But instead of setting up the Colossus again, for which purpose the greatest part of it was given, they pretended that the oracle of Delphos had forbidden it, and converted the money to other uses. Accordingly the Colossus lay neglected on the ground for the space of 894 years, at the expiration of which period, or about the year of our Lord 653, or 672, Moawyas, the 6th caliph or emperor of the Saracens, made himself master of Rhodes, and afterwards sold their statue, reduced to fragments, to a Jewish merchant, who loaded 900 camels with the metal, so that, allowing 800 pounds weight for each load, the brass of the Colossus, after the diminution which it had sustained by rust, and probably by theft, amounted to 720 thousand pounds weight. The basis that supported it was of a triangular figure: its extremities were sustained by sixty pillars of marble. There was a winding staircase to go up to the top of it; from whence one might discover Syria, and the ships that went to Egypt, in a great looking-glass, that was hung about the neck of the statue. This enormous statue was not the only one that attracted attention in the city of Rhodes. Pliny reckons 100 other colossuses not so large, which rose majestically in its different quarters.

COLOUR means that property of bodies which affects the sight only; thus the grass in the fields has a green colour, blood has a red colour, the sky generally appears of a blue colour, and so forth: nor can those colours be distinguished by any of our other senses besides the sight. The variety of colours, as they are presented to us by the substances that surround us, is immense, and from them arises the admirable beauty of the works of nature in the animal, in the vegetable, and in the mineral kingdom, or, more properly speaking, in the universe. The science which examines and explains the various properties of the colours of light and of natural bodies, and which forms a

I i

Or and argent are metals; and it is an invariable rule in heraldry not to put colour upon colour, or metal on metal: that is, if the field be of a colour, the charge or bearing must be of a metal.

COLOUR, in law, is a probable or plausible plea, though in reality false at bottom, and only calculated to draw the trial of the cause from the jury to the judge; and therefore colour ought to be matter of law, or doubtful to the jury.

In pleading, it is a rule that no man be allowed to plead specially such a plea as amounts only to the general issue; but in such case he shall be driven to plead the general issue, in terms by which the whole question is referred to a jury. But if a defendant in an assize, or action of trespass, be desirous to refer the validity of his title to the court rather than to the jury, he may state his title specially, and at the same time give colour to the plaintiff; or suppose him to have an appearance or colour of title, bad indeed in point of law, but of which the jury are not competent judges.

COLOUR, in calico-printing. The term colour in calico-printing isapplied not only to those vegetable, animal, and mineral solutions, which impart their own colour to the cloth on which they are applied, but also improperly to those earthy or metallic solutions, which, possessing little or no tingent properties themselves, yet retain or fix the qualities (colours) of other substances, when afterwards applied to the

Dragon'shead. Dragon's tail.

cloth. Thus the acetite of alumina, or prin ter's red liquor, when pure, is almost colourless, and only becomes red by the process of dyeing, as will be explained hereafter. The acetite of iron, or iron liquor, in like manner, when used of a determi -nate strength, is called black colour, and when weaker, purple colour, though the cloth impregnated with these solutions becomes black or purple, only as being raised like the other in the dye-copper. 1. The colours produced by means of these earthy or metallic solutions (which in the language of science are called mor dants) form the most valuable and impor tant series, whether considered with regard to the almost infinite variety of shades, or to their solidity and durability. These colours, from the mode in which they are produced, (the mordant being first applied to the cloth, and the colour afterwards raised by dyeing,) are called dyed colours. 2. Sometimes the mordant is previously mixed with a solution of colouring matter, and in that state applied to the cloth, so as to paint or stain it at one operation and without the process of dyeing. Thus another class of colours is produced, many of them possessing great brilliancy indeed, but much inferior to the former in durability. The colours called chemical by calico-printers belong chiefly to this class. 3. In the third and last class we may place all those, where the colouring matter is simply held in solu tion by an acid or alkali, and in this state

applied to the cloth without the intervention of any mordant. To one or other of the foregoing classes may be referred all the colours used in calico-printing, with the exception, however, of those systems of colours which have been produced by calico-printers in this country, within a short period, by processes and upon principles which have hitherto not been made known. See CALICO-PRINT

ING.

COLOUR of the clouds is thus accounted for by Sir Isaac Newton. Concluding, from a series of experiments, that the transparent parts of bodies, according to their several sizes, reflect rays of one colour, and transmit those of another, he hence observes, that when vapours are first raised, they are divided into parts too small to cause any reflection at their surfaces, and therefore do not hinder the transparency of the air; but when they begin to coalesce, in order to form drops of rain, and constitute globules of all intermediate sizes, these globules are capable of reflecting some colours, and transmitting others, and thus form clouds of various colours, according to their sizes. Mr. Melville controverts this doctrine, in its application to the red colour of the morning and evening clouds. "Why," he says, "should the particles of the clouds become at that particular time, and never at any other, of such a magnitude as to separate these colours? And why are they rarely, if ever, seen tinc tured with blue and green, as well as red, orange, or yellow? Is it not more credible, that the separation of rays is made in passing through the horizontal atmosphere, and that the clouds only reflect and transmit the sun's light, as any halftransparent colourless body would do? For since the atmosphere reflects a greater quantity of blue and violet rays than of the rest, the sun's light transmitted through it ought to incline towards yellow,orange,or red; especially when it passes through a long tract of air: and thus it is found, that the sun's horizontal light is tinctured with a deep orange, and even red; and the colour becomes still deeper after sun-set.” Hence he concludes that the clouds, according to their different altitudes, may assume all the variety of colours at sunrising and setting, by barely reflecting the sun's incident light as they receive it. COLOURS. This very important article includes a variety of matters of peculiar interest to various professions, and requiring no inconsiderable portion of study. We have only seven natural colours,

namely, red, orange, yellow, green, blue, indigo, and violet. See CHROMATICS.

The mathematical use of colours is more immediately under our present consideration. These are either what are called body, or transparent: the former applies to such as have a certain substance, being like very thin paste, and coating the object to which they are applied: these are again divided into oil and water colours. Transparent colours are made either of expressed juices, corrected by inspissation, or of the finer particles of earths, gums, &c. highly prepared by levigation, washing, &c.

Oil colours are made by mixing the colouring substances with prepared oils; that is, such as dry readily, and are at the same time so fine and transparent as not to injure the brilliancy or clearness of the colour. Nut-oil is on this account highly esteemed; but in a recent publication (the seventh number of the Agricultural Magazine) we are informed, that sun-flower oil posscsses qualities of great moment to the painter, and to various other artists. The colouring matter must be minutely mixed with the oil, so that it may work perfectly free and smooth.

Body colours for the limner's use should be prepared of the purest materials, and be triturated in a mortar, and on a slab with water, until such time as the mixture is completely smooth,and leaves no roughness when rubbed between the thumb and fore-finger: not, however, without making allowance for some particular substances, especially minerals, which, however well they may have been prepared, will occasion a roughness to the touch. Body colours are usually sold in bottles, ready mixed to their proper consistence, and sometimes in cakes, with a small portion of gum Arabic dissolved in the water. Oil colours are most frequently sold in kegs, and ready ground, but requiring an addition of oil before they can be worked: these are generally for the use of house painters, &c.: those for the more delicate purposes are usually kept in bladders.

Transparent colours should be so clear, when mixed with abundance of water, as to communicate a strong tint, without in the smallest degree plastering or concealing the paper, &c.: hence their designation. The best of every kind are made from either vegetable or animal substances; minerals being extremely difficult to prepare, equally so to work with water, and many of them very subject to change. We shall give a concise account of the