a general sense, any glutinous substance capable of uniting and keeping things together in close cohesion. In this sense the word cement comprehends mortar, solder, glue, &c. but has been generally restrained to the compositions used for holding together broken glasses, china, and earthen ware. For this purpose the juice of garlic is recommended as exceedingly proper, being both very strong, and, if the operation is performed with care, leaving little or no mark. Quicklime and the white of an egg mixed together and expediently used, are also very proper for this purpose. Dr Lewis recommends a mixture of quicklime and cheese in the following manner: "Sweet cheese shaved thin, and stirred with boiling-hot water, changes into a tenacious slime which does not mingle with the water. Worked with fresh particles of hot water, and then mixed upon a hot stone with a proper quantity of unflaked lime, to the consistence of a paste, it proves a strong and durable cement for wood, stone, earthen ware, and glasses. When thoroughly dry, which will be in two or three days, it is not in the least acted upon by water. Cheese barely beat with quicklime, as directed by some of the chemists for luting cracked glasses, is not near so efficacious." A composition of the drying oil of linseed and white lead is also used for the same purposes, but is greatly inferior.

building, is used to denote any kind of mortar of a stronger kind than ordinary. The cement commonly used is of two kinds; hot and cold. The hot cement is made of rosin, bees-wax, brick-dust, and chalk boiled together. The bricks to be cemented are heated, and rubbed one upon another, with cement between them. The cold cement is that above described for cementing china, &c. which is sometimes, though rarely, employed in building.

The ruins of the ancient Roman buildings are found to cohere so strongly, that most people have imagined the ancients were acquainted with some kind of mortar, which, in comparison of ours, might justly be called cement; and that to our want of knowledge of the materials they used, is owing the great inferiority of modern buildings in their durability. In 1777, one M. Loriot, a Frenchman, pretended to have discovered the secret of the ancient cement, which, according to him, was no more than a mixture of powdered quicklime with lime which had been long flaked and kept under water. The flaked lime was first to be made up with sand, earth, brickdust, &c., into mortar after the common method, and then about a third part of quicklime in powder was added to the mixture. This produced an almost instantaneous precipitation, something like what is called the setting of alabaster, but in a much stronger degree; and was possessed of many wonderful qualities needless here to relate, seeing it has never been known to succeed with any other person who tried it. Mr Anderson, in his essays on agriculture, has discussed this subject at considerable length, and seemingly with great judgment. He is the only person we know who has given any rational theory of the uses of lime in building, and why it comes to be the proper basis of all cements. His account is in substance as follows:

Lime which has been flaked and mixed with sand, becomes hard and consistent when dry, by a process similar to that which produces the natural stalactites in caverns. These are always formed by water dripping from the roof. By some unknown and inexplicable process of nature, this water has dissolved in it a small portion of calcareous matter in a caustic state. As long as the water continues covered from the air, it keeps the earth dissolved in it; it being the natural property of calcareous earths, when deprived of their fixed air, to dissolve in water. But when the small drop of water comes to be exposed to the air, the calcareous matter contained in it begins to attract the fixable part of the atmosphere. In proportion as it does so, it also begins to separate from the water, and to assume its native form of limestone or marble. This process Mr Anderson calls a crystallization; and when the calcareous matter is perfectly crystallized in this manner, he affirms, that it is to all intents and purposes lime—one or marble of the same consistence as before; and "in this manner (says he), within the memory of man, have huge rocks of marble been formed near Marlock in Derbyshire." If lime in a caustic state is mixed with water, part of the lime will be dissolved, and will also begin to crystallize. The water which parted with the crystallized lime will then begin to act upon the remainder, which it could not dissolve before; and thus the process will continue, either till the lime be all reduced to an efflorescence, or (as he calls it) crystalline state, or something hinders the action of the water upon it. It is this crystallization which is observed by the workmen when a heap of lime is mixed with water, and left for some time to macerate. A hard crust is formed upon the surface, which is ignorantly called flaking, though it takes place in summer as well as in winter. If therefore the hardness of the lime, or its becoming a cement, depends entirely on the formation of its crystals, it is evident that the perfection of the cement must depend on the perfection of the crystals, and the hardness of the matters which are entangled among them. The additional substances used in making of mortar, such as sand, brickdust, or the like, according to Mr Anderson, serve only for a purpose similar to what is answered by sticks put into a vessel full of any saline solution, namely, to afford the crystals an opportunity of settling themselves upon it. If therefore the matter interposed between the crystals of the lime is of a friable, brittle nature, such as brickdust or chalk, the mortar will be of a weak and imperfect kind; but, when the particles are hard, angular, and very difficult to be broken, such as those of river or pit sand, the mortar turns out exceedingly good and strong. Sea sand is found to be an improper material for mortar, which Mr Anderson attributes to its being less angular than the other kinds. That the crystallization may be the more perfect, he also recommends a large quantity of water, that the ingredients be perfectly mixed together, and that the drying be as slow as possible. An attention to these circumstances, he thinks, would make the buildings of the moderns equally durable with those of the ancients; and from what remains of the ancient Roman works, he thinks a very strong proof of his hypothesis might be adduced. The great thickness of their walls necessarily required a vast length of time to dry. The middle of them was composed of pebbles thrown in at random, and which have evidently had mortar so thin as to be poured in among them. By this means a great quantity of the lime would be dissolved, and the crystallization performed in the most perfect manner; and the indefatigable pains and perseverance for which the Romans were so remarkable in all their undertakings, leave no room to doubt that they would take care to have the ingredients mixed together as well as possible. The consequence of all this is, that the buildings formed in this manner are all as firm as if cut out of a solid rock; the mortar being equally hard, if not more so, than the stones themselves.

Notwithstanding the bad success of those who have attempted to repeat M. Loriot's experiments, however, Dr Black informs us, that a cement of this kind is certainly practicable. It is done, he says, by powdering the lime while hot from the kiln, and throwing it into a thin paste of sand and water; which, not flaking immediately, absorbs the water from the mortar by degrees, and forms a very hard mass. "It is plain," he adds, "that the strength of this mortar depends on using the lime hot or fresh from the kiln."

By mixing together gypsum and quicklime, and then adding water, we may form a cement of tolerable hardness, and which apparently might be used to advantage in making troughs for holding water, or lining small canals for it to run in. Mr Wiegley says, that a good mortar or cement, which will not crack, may be obtained by mixing three parts of a thin magma of flaked lime with one of powdered gypsum; but adds, that it is used only in a dry situation. A mixture of tar with flaked lime acquires in time a stony hardness, and may be used for preventing water from entering. See Mortar and Stucco.

Cement, among engravers, jewellers, &c., is the same with the hot cement used in building; and is used for keeping the metals to be engraved firm to the foregoing block, and also for filling up what is to be chiselled.

Chemistry, is used to signify all those powders... Cement powders and pastes with which any body is surrounded in pots or crucibles, and which are capable by the help of fire of producing changes upon that body. They are made of various materials; and are used for different purposes, as for parting gold from silver, converting it into steel, copper into brass: and by cementation more considerable changes can be effected upon bodies, than by applying to them liquids of any kind; because the active matters are then in a state of vapour, and assisted by a very considerable degree of heat.

**Cement which quickly hardens in water.** This is described in the posthumous works of Mr Hooke, and is recommended for gilding live craw fish, carp, &c., without injuring the fish. The cement for this purpose is prepared, by putting some Burgundy pitch into a new earthen pot, and warming the vessel till it receives so much of the pitch as will stick round it, then strewing some finely-powdered amber over the pitch when growing cold, adding a mixture of three pounds of linseed oil, and one of oil of turpentine, covering the vessel and boiling them for an hour over a gentle fire, and grinding the mixture as it is wanted with as much pumice-stone in fine powder as will reduce it to the consistence of paint. The fish being wiped dry, the mixture is spread upon it; and the gold leaf being then laid on, the fish may be immediately put into water again, without any danger of the gold coming off, for the matter quickly grows hard in the water.

**Cement Pots,** are those earthen pots used in the cementation of metals.

**Cementation,** the act of corroding or otherwise changing a metal by means of a Cement.

**Cemetery** (κοιμητήριον, from κοιμάσθαι, to "sleep"); a place set apart or consecrated for the burial of the dead.

Anciently none were buried in churches or churchyards: it was even unlawful to inter in cities, and the cemeteries were without the walls. Among the primitive Christians these were held in great veneration. It even appears from Eusebius and Tertullian, that, in the early ages, they assembled for divine worship in the cemeteries. Valerian seems to have confiscated the cemeteries and other places of divine worship, but they were restored again by Gallicius. As the martyrs were buried in these places, the Christians chose them for building churches on, when Constantine established their religion; and hence some derive the rule which still obtains in the church of Rome, never to consecrate an altar without putting under it the relics of some saint. The practice of consecrating cemeteries is of some antiquity. The bishop walked round it in procession, with the crozier or pastoral staff in his hand, the holy water pot being carried before, out of which the absolutions were made.

**Cenchrus.** See Botany Index.

**Cenegild,** in the Saxon antiquities, an expiatory mulct, paid by one who had killed a man to the kindred of the deceased. The word is compounded of the Saxon cinne, i.e. cognatio, "relation," and gild, solutio, "payment."

**Cenobite.** See Coenobite.

**Cenotaph,** in antiquity, an empty tomb, erected by way of honour to the deceased. It is distinguished from a sepulchre, in which a coffin was deposited. Of these there were two sorts; one for those who had, and another for those who had not, been honoured with funeral rites in another place.

The sign whereby honorary sepulchres were distinguished from others, was commonly the wreck of a ship, to denote the decease of the person in some foreign country.

**Censer,** in antiquity, a vase containing incense to be used in sacrifices. Censer is chiefly used in speaking of the Jewish worship. Among the Greeks and Romans it is more frequently called thuribulum, λευκαρνα, and acerra.

The Jewish censer was a small sort of chafing dish, covered with a dome, and suspended by a chain. Josephus tells us, that Solomon made 20,000 gold censers for the temple of Jerusalem, to offer perfumes in, and 50,000 others to carry fire in.

**Censio,** in antiquity, the act or office of the censor. See Census.

Censio included both the rating or valuing a man's estate, and the imposing mulcts and penalties.

**Censio hastaria,** a punishment inflicted on a Roman soldiery for some offence, as laziness or luxury, whereby his hæta or spear was taken from him, and consequently his wages and hopes of preferment stopped.

**Censitus,** a person censed, or entered in the census tables. See Census.

In an ancient monument found at Ancyra, containing the actions of the emperor Octavius, we read,

> Quo lustro civium Romanorum > Centia sunt capitae quadrages > Centum millia et sexaginta tria.

Censitus is also used in the civil law for a servile sort of tenant, who pays capitation to his lord for the lands he holds of him, and is entered as such in the lord's rent roll. In which sense, the word amounts to the same with capite censi, or capite censitis. See Capite Censi.

**Censor,** (from censere to "think" or "judge"); one of the prime magistrates in ancient Rome.—Their business was to register the effects of the Roman citizens, to impose taxes in proportion to what each man possessed, and to take cognizance or inspection of the manners of the citizens. In consequence of this last part of their office, they had a power to censure vice or immorality, by inflicting some public mark of ignominy on the offender. They had even a power to create the princeps senatus, and to expel from the senate such as they deemed unworthy of that office. This power they sometimes exercised without sufficient grounds; and therefore a law was at length passed, that no senator should be degraded or disgraced in any manner until he had been formally accused and found guilty by both the censors. It was also a part of the censorian jurisdiction, to fill up the vacancies in the senate, upon any remarkable deficiency in their number; to let out to farm all the lands, revenues, and customs, of the republic; and to contract with artificers for the charge of building and repairing all the public works and edifices both in Rome and the colonies of Italy. In all parts of their office, however, they were subject to the jurisdiction of the people; and an appeal always lay from the sentence of the censors to that of an assembly of the people.

The first two censors were created in the year of Rome 311, upon the senate's observing that the consuls were too much taken up with war as not to have time to look into other matters. The office continued to the time of the emperors, who assumed the censorial power, calling themselves *morum praefecti*; though Vespasian and his sons took the title of censors. Decius attempted to restore the dignity to a particular magistrate. After this we hear no more of it, till Constantine's time, who made his brother censor, and he seems to have been the last that enjoyed the office.

The office of censor was so considerable, that for a long time none aspired to it till they had passed all the rest; so that it was thought surprising that Cælius should be admitted censor, without having been either consul or praetor. At first the censors enjoyed their dignity for five years, but in 420 the dictator Mamercus made a law restraining it to a year and a half, which was afterwards observed very strictly. At first one of the censors was elected out of a patrician, and the other out of a plebeian family; and upon the death of either, the other was discharged from his office, and two new ones elected, but not till the next lustrum. In the year of Rome 622, both censors were chosen from among the plebeians; and after that time the office was shared between the senate and people. After their election in the Comitia Centuriata, the censors proceeded to the capitol, where they took an oath not to manage either by favour or disaffection, but to act equitably and impartially throughout the whole course of their administration.

The republic of Venice still has a censor of the manners of their people, whose office lasts six months.

**Censors of Books**, are a body of doctors or others established in divers countries to examine all books before they go to the press, and to see they contain nothing contrary to faith and good manners.

At Paris, before the late revolution, the faculty of theology claimed this privilege as granted to them by the pope; but, in 1624, new commissions of four doctors were created, by letters patent, the sole censors of all books, and answerable for every thing contained therein.

In England, we had formerly an officer of this kind, under the title of licensor of the press; but, since the Revolution, our press has been laid under no such restraint.

**Censorinus**, a celebrated writer in the third century, well known by his treatise *De die Natali*. This treatise, which was written about the year 238, Gerard Vossius calls a little book of gold; and declares it to be a most learned work, of the highest use and importance to chronologers, since it connects and determines, with great exactness, some of the principal eras in pagan history. It was printed at Cambridge, with the notes of Lindenbrokius, in 1695.

**Censure**, a judgment which condemns some book, person, or action, or more particularly, a reprimand from a superior. Ecclesiastical censures are penalties, by which, for some remarkable misbehaviour, Christians are deprived of the communion of the church, or prohibited to exercise the sacerdotal office.

**Census**, in Roman antiquity, an authentic declaration made before the censors, by the several subjects of the empire, of their respective names and places of abode. This declaration was registered by the censors; and contained an enumeration, in writing, of all the estates, lands, and inheritances they possessed; their quantity, quality, place, wives, children, domestics, tenants, slaves. In the provinces the census served not only to discover the substance of each person, but where, and in what manner and proportion, taxes might be best imposed. The census at Rome is commonly thought to have been held every five years; but Dr Middleton hath shown, that both census and lustrum were held irregularly and uncertainly at various intervals. The census was an excellent expedient for discovering the strength of the state; for by it they discovered the number of the citizens, how many were fit for war, and how many for offices of other kinds; how much each was able to pay of taxes, &c. It went through all ranks of people, though under different names: that of the common people was called *census*; that of the knights, *centurio, recensio, recognitio*; that of the senators, *lectio, relatio*. Hence also *census* came to signify a person who had made such a declaration; in which sense it was opposed to *incensus*, a person who had not given in his estate or name to be registered.

The census, according to Salmatius, was peculiar to the city of Rome. That in the provinces was properly called *proficio* and *apovagyn*. But this distinction is not everywhere observed by the ancients themselves.

**Census** was also used for the book or register wherein the professions of the people were entered: in which sense, the census was frequently cited and appealed to as evidence in the courts of justice.

**Census** is also used to denote a man's whole substance or estate.

**Census Senatorius**, the patrimony of a senator, which was limited to a certain value; being at first rated at 800,000 sesterces, but afterwards, under Augustus, enlarged to 1,200,000.

**Census Equitum**, the estate or patrimony of a knight, rated at 400,000 sesterces, which was required to qualify a person for that order, and without which no virtue or merit was available.

**Census** was also used for a person worth 100,000 sesterces, or who was entered as such in the census tables, on his own declaration. In which sense, census amounts to the same with *classeus*, or a man of the first class; though Gellius limits the estate of those of this class to 125,000 asses. By the Viconian law, no census was allowed to give by his will above a fourth part of what he was worth to a woman.

**Census** was also used to denote a tax or tribute imposed on persons, and called also capitation. See *Capite Censi*.

**Census Dominicatus**, in writers of the lower age, denotes a rent due to the lord.

**Census Duplicitus**, a double rent or tax, paid by vassals to their lord on extraordinary or urgent occasions; as expeditions to the Holy Land, &c.

**Census Ecclesiae Romanae**, was an annual contribution voluntarily paid to the see of Rome by the several princes of Europe.