Slike strani


native of the interior of Chili, living underground like the mole, which it much resembles in its habits, and feeding on the same kind of food. Its fore-feet are adapted for digging, although in a different manner from those of the mole. The skull is destitute of sutures; there are resemblances to the


osteology of birds in the ribs and their union to the sternum; the hinder part of the body is altogether unlike that of any other known animal, in its terminating quite abruptly, as if cut off almost where its thickness is greatest, or as if the back were suddenly bent down at right angles, the tail not springing from where the line of the back appears to terminate, but far below. The whole upper and hinder parts of the body are covered with a coat of mail, made up of a series of square plates; the under parts and legs are covered with long silky hair. The tail is very peculiar it is covered with small scales, is expanded at the tip, and is usually incurved along the belly, but is furnished with such muscles as to suggest the probability of its being employed to throw back the


earth in excavations.

CHLORAL is a limpid, colourless, oily liquid, with a peculiar penetrating odour, and is formed when anhydrous alcohol is acted on by dry chlorine gas. It dissolves sulphur, phosphorus, bromine, and iodine, and is closely allied to aldehyde. C. combined with one equivalent of water forms chloral hydrate, often popularly called chloral. C. was discovered by Liebig in 1831, and investigated by Dumas; the C. hydrate was first used as an anæsthetic and hypnotic by Liebreich in 1869. Though now often abused by being taken recklessly as a narcotic, C. hydrate is a valuable addition to the pharmacopeia; it is used to procure sleep in insomnia, and in various nervous diseases, insanity, delirium tremens, neuralgia, and strychnia poisoning. The average dose is from 15 to 30 grains; an overdose will cause death.

CHLORANTHACEA, a natural order of exogenous plants, closely allied to the peppers; herbaceous and half-shrubby plants.-The number of known species is small: all of them are tropical, or natives of China and Japan. They are generally aromatic, and some of them are used as antispasmodics, stimulants, stomachics, and tonics. The roots of Chloranthus officinalis and C. brachystachys have been ranked among the most efficacious remedies in fevers and other diseases requiring continual and active stimulants, and instances have occurred of great benefit from their employment during the prevalence of epidemics in Java. C. inconspicuus is the CHU-LAN of the Chinese; its leaves, spikes of flowers, and berries are used by them for imparting a peculiar fragrance to tea. All the teas which have what is called the cowslip flavour owe it to this plant.

atom of chlorine and five atoms of oxygen, and CHLO'RIC ACID (ClO) is a compound of one is generally met with in combination with potash, as the white crystalline salt, chlorate of potash (KO,CIO,). This salt is mainly interesting from the readiness with which it parts with its oxygen to combustibles, as when thrown on red-hot charcoal, when it causes violent deflagration. The salt is employed in the fabrication of certain kinds of lucifer-matches, which give a slight explosion when struck. If a crystal of chlorate of potash be placed on a piece of paper saturated with turpentine, and a drop or two of oil of vitriol added, it causes the inflaming of the turpentine with explosive rapidity. The chlorate of potash is also used in medicine, with the view of imparting oxygen to the blood.

CHLOPICKI, JOSEPH, a Polish general, and Dictator of Poland during the revolution of 1830, was born in Galicia in 1772. He entered the army in 1787, attracted the notice of Kosciusko during the first insurrection of the Poles, and after the storming of Praga, 9th November 1794, when the hopes of the patriots were extinguished for awhile, he passed into the service of the new Cisalpine Republic, and distinguished himself in various battles. In 1806 when Bonaparte called the Poles to arms, C., among others, obeyed, and fought gallantly at Eylau and Friedland. He was subsequently sent CHLORIMETRY, or CHLORO'METRY, is by the emperor into Spain, and in 1812 followed him the process of estimating the proportion of available to Russia, taking part in the bloody engagements chlorine in bleaching powder (q. v.), which may at Smolensk and Moskwa. After the relics of the vary from 20 to 36 per cent. The process depends invading force had returned, C. left the imperial upon the great power with which chlorine, in the service, on account of receiving certain slights in act of being liberated from its compounds, causes the way of his professional advancement. After the oxidation of many substances. The salt genethe taking of Paris by the allies in 1814, he led back rally used is pure crystallised sulphate of iron, to Poland the remains of the Polish troops who had which, in its ordinary state, gives a deep blue fought under Bonaparte, and was well received by colour, with a drop of ferridcyanide of potassium, the Emperor Alexander, who made him a general of but ceases to do so when it has been fully oxidised, division. When the second insurrection of the or converted from a proto-salt into a per-salt, Poles broke out in 1830, C., who foresaw the hope- through the influence of chlorine. It being known less nature of the attempt, concealed himself; but that 78 grains or parts of sulphate of iron are the voice of the nation called him forth from his oxidised by 10 grains or parts of chlorine, the mode hiding-place, and on the 5th December 1830, he was of procedure in C. is as follows: 78 grains of elected dictator. His moderate views, however, fine crystals of the sulphate of iron are dissolved involved him in disputes with the extreme patriotic in water slightly acidulated with hydrochloric acid party, and on the 23d January 1831, he resigned his in a white porcelain basin. A given quantity of office; but he entered the Polish army as a simple the bleaching powder-say 50 grains-is dissolved soldier, and fought at Wavre and Grochow. He in a little tepid water, and introduced into a tall afterwards retired into private life, and died 30th measure-glass called a chlorimeter or burette (figs. 1, September 1854. 2, and 3), similar to an alkalimeter, which is divided


into 100 parts, and water added till the solution
rises to the top mark. After subsidence of the
insoluble matter, the
clear solution is very
gradually poured into the
solution of sulphate of
iron in the basin, the
O whole being kept con-
10stantly stirred, and every
now and again a drop of
20 the iron solution is taken
30 out and placed on a new
drop of ferridcyanide of
potassium placed on a
50 white plate; and when-
ever the iron solution
ceases to produce a deep
70 blue, and only forms a
light greenish-yellow tint,
it is known that the iron
90 has been fully oxidised
by the chlorine. Suppose
that at this stage the
burette has been emptied
to the 55th division; as
we know that the liquid poured out must have
contained 10 grains of chlorine, we can calculate
the chlorine contained in the whole; for


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30 40






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55 10:100: 18.18.

Thus 50 grains of the powder contain 18:18 grains of chlorine, or 36.36 per cent. Protochloride of manganese, subchloride of mercury (calomel), or a solution of indigo of known strength, may be employed instead of the sulphate of iron; but the latter is preferable, and is generally employed by chemists and manufacturers.


powerful disinfectant (q. v.). The gas can be condensed by pressure and cold into a transparent dark greenish-yellow limpid liquid, with a specific gravity of 1330 (HO 1000), which also possesses bleaching properties, and a most powerful odour. On the animal system C. acts, in very minute quan. tity, by producing a sensation of warmth in the respiratory passages, and increasing the expector ation; in large quantity, by causing spasm of the glottis, violent cough, and a feeling of suffocation. The workmen in chemical manufactories, who get accustomed to the C. in small quantity, are generally stout-at least, lay on fat-but complain of acidity in the stomach, which they correct by taking chalk, and also suffer from the corrosion of their teeth, which are eaten away to stumps. The antidotes to the evil effects of the introduction of C. into the lungs are the inhalation of the vapour of water, alcohol, ether, or chloroform; but the two latter should never be resorted to except under medical supervision.

C. unites with the metals and many other substances to form an extensive class of salts known as chlorides.

CHLO'RITE (Gr. chloros, green), an abundant mineral, consisting of silica, alumina, magnesia, and protoxide of iron, in somewhat variable proportions. It is of a green colour, rarely occurs crystallised in hexagonal crystals, sometimes foliated like talc. It is rather soft, and is easily broken or scratched with a knife. Before the blowpipe, it is with difficulty fused on thin edges. It is readily distinguished from tale by yielding water in a closed tube.

CHLO'RITE-SCHIST, or CHLORITE-SLATE, a green slaty rock, in which chlorite is abundant in foliated plates, usually blended with minute grains of quartz, and sometimes with felspar or mica.


CHLORINE (Gr. chloros, pale green) is a nonmetallic element discovered by Scheele in 1774, and named by him dephlogisticated marine air. Afterwards, in 1810, Davy proved it to be an elementary body, and gave it the name which it now bears. In nature it is always found in a state of combination. United with sodium (Na), it occurs very largely as the chloride of sodium (NaCl)-common salt in the ocean; in large beds, as rock-salt; in all natural waters, including even rain-water; in clays, soils, limestone; in volcanic incrustations; and in the vegetable and animal kingdoms. The preparation of gaseous C. by its liberation, directly or indirectly, from common salt, has been fully described under BLEACHING POWDER, which is the form in which C. is prepared and employed commercially. For experimental purposes, the gas may be received in jars filled with water at the pneumatic trough, when the C. rises into the jar, and displaces the water. When thus obtained, it is a yellowish-green gas with a peculiar and suffocating odour, is not combustible, and a very feeble supporter of ordinary combustion. A lighted candle placed in it burns with a very smoky flame, owing to the hydrogen of the oil alone burning, and the carbon being liberated. Several of the metals, such as antimony, copper, and arsenic, in a fine state of division, or in the condition of thin leaves, at once become red hot, and burn when introduced into the gas. A piece of thin paper soaked in turpentine likewise bursts into flame. C. has the symbol Cl, and the atomic weight or equivalent of 35.5. It is a very heavy gas, nearly 2 times heavier than air, its specific gravity being 2470 (air 1000); it is soluble in cold water to the extent of two volumes of C. in one of water, and yields a solution resem-It has a specific gravity of nearly 1500 (water bling the gas in colour, odour, and other properties. 1000), being thus half as heavy again as water, The principal properties of C. are those of a bleacher and boils at 140° F. It is not inflammable in the of cotton and linen (see BLEACHING), and a most ordinary sense of the term, as it will not take fire

C. is a highly limpid, mobile, colourless liquid, which is very volatile, has a characteristic and pleasant odour, and an agreeable sweetish taste.

CHLOROFORM, or the TERCHLO'RIDE OF FO'RMYLE (C,HCI,), was originally discovered by Soubeiran, and experimented upon by Dumas, and was long known only to scientific chemists as a rare organic body, possessing interest from being one of a series of organic substances, but not known to possess any properties likely to call it into use, or even likely to let it be known by name to the general public. The remarkable power, however, which it possesses of producing anesthesia, has led to the preparation of C. on a very extensive scale. The materials employed are alcohol, water, and bleaching powder, and the proportions are four parts of bleaching powder, to which sufficient water is added to make a thin paste, and thereafter one part of spirits of wine; the whole is introduced into a capacious retort, which must not be more than half filled, and heat being applied, the C., accompanied by water and a little alcohol, distils over. As the C. is heavier than water, and is not readily miscible therewith, two layers of liquid are obtained in the receiver-the upper being water and alcohol, and the lower being chloroform. The upper liquid being cautiously poured off, the C. is agitated with fused carbonate of potash, which abstracts the remaining traces of water, and on subsequent redistillation the C. is obtained pure and ready for use.


when a light is brought down upon it; but when perish from it, or are much diminished in value. thrown on red-hot coals, it burns with a green Fruit-trees also suffer from it. flame, evolving much smoke. It is slightly soluble in water, but more readily mixes with alcohol and ether. It dissolves camphor, amber, copal, and other resins, wax, caoutchouc, black and red sealing wax, iodine and bromine, as well as strychnine and other alkaloids. Its purity may be determined by placing some on the palm of the hand, and allowing it to evaporate, when no alcoholic or other odorous substance should be even momentarily recognised; and by agitation with oil of vitriol, when, on settling, the C. should readily swim on the surface of the vitriol, and the two layers of liquid remain colourless. The employment of C. as an anesthetic has already been considered under ANESTHESIA; but it may be here repeated,

that C. is a substance that cannot be too cautiously dealt with, and that it should never be administered except in the presence and by the sanction of a medical practitioner. When skilfully given, it is among the safest of all anæsthetics, and the greatest boon that chemistry has bestowed on suffering humanity.

CHLOROPHYLL (Gr. chloros, green, and phyllon, a leaf), the substance to which the leaves and other parts of plants owe their green colour. It is somewhat analogous to wax, is soluble in alcohol and ether, but insoluble in water, and floats in the fluid of the cells, in the form of minute granules. Light is indispensable to its formation, and hence arises the familiar phenomenon of Blanching (q. v.), either from accidental causes, or by the art of the gardener. Young leaves do not exhibit so deep a green as those which have been longer exposed to the light; and the green of a leaf generally deepens till it begins to change into the tints of autumn. Hydra viridis, and other minute animals, appear to owe their green colour to a substance analogous to chlorophyll.


CHLORO'SIS (Gr. chloros, pale green), a peculiar form of anæmia or bloodlessness, common in young women, and connected with the disorders incident to the critical period of life. It has been called the green sickness, from the peculiar dingy greenish-yellow hue of the complexion; the green colour, however, is not always characteristic. The disease is attended with very great debility, and often with breathlessness, palpitation, and other distressing, or even alarming symptoms. When there is no organic disease present, however, C. may be pronounced curable in a large proportion of cases. The principal means to be employed are air, exercise, often salt-water baths, the use of iron, with a nutritious and rather stimulating diet, and purgatives if required; together with such special remedies as are adapted for restoring deficient secretions, and bringing the entire female system of organs into a

natural condition.

CHLORO'SIS, a diseased state of plants, in which a sickly green or greenish-yellow colour takes the place of the natural lively hue. Sometimes only a particular shoot is affected by it, but very generally the whole plant; and it seems to depend upon causes which render the plant altogether unhealthy, the pallid appearance being merely symptomatic, and not only the formation of chlorophyll, but all the functions of vegetable life being languidly and imperfectly carried on. Bad seed, damp soil, and cold wet weather, appear to be the most common causes of chlorosis. Plants affected by this disease are often to be seen among crops generally healthy; but whole crops of grain, potatoes, &c., sometimes

CHOCARD, or CHOQUARD (Pyrrhocorax), a genus of birds of the Crow family (Corvida), differing from the Choughs in having a shorter bill, which, however, is arched like theirs, but resembling them their habits. The only European species is the Alpine C., also called Alpine Chough, and Alpine Crow (P. Pyrrhocorax). It is about the size of a jackdaw, of a brilliant black, with yellowish bill and red feet.

CHOCKS are pieces of wood employed on ship-board to aid in the support of various articles. Amongst them are anchor-chocks, rudder-chocks, boat-chocks, stow-wood chocks, and chocks to support the ends of the beams.

CHO'CO, a bay and province of New Granada, in South America.-1. The bay, forming part of the Gulf of Darien, receives the Atrato (q. v.), a stream of note in connection with inter-oceanic communication. Its lat. and long, are about 3° 30′ N., and 77° 30′ W.-2. The province forms the west portion of the department of Cauca (q. v.).

CHO'COLATE is made from the seeds of Theo

broma Cacao (see Cocoa), reduced to a fine paste in a heated iron mortar, or by a machine, and mixed with pounded sugar and spices, as cinnamon, cloves, cardamom, vanilla, &c. The paste is then poured into moulds of white iron, in which it is allowed to cool and harden. C. is sometimes made without spices, but is then more generally called Cocoa. The paste is sometimes mixed with flour, and with Carrageen or with Iceland Moss; and for medicinal purposes with cinchona, &c. C. is used as a beverage, and for this purpose is dissolved in hot water or milk. Sometimes the yolk of an egg is added, and sometimes it is dissolved in soup or wine. It is also employed in making certain liqueurs. In a pure state, it soon satisfies the appetite, and is very nourishing; when it contains spices, it is also stimulating. Good C. is externally smooth, firm, and shiningnot gritty in the fracture-easily soluble, aromatic; not viscid after having been liquefied and cooled, but oily on the surface, and leaves no sediment of foreign substances. C. is adulterated in many ways, by mixing it with rice-meal, oatmeal, flour, potato-starch, roasted hazel-nuts or almonds, and with benzoin, storax, &c., in place of vanilla. The Mexicans, from time immemorial, were accustomed to prepare a beverage from roasted and pounded cocoa, dissolved in water, and mixed with maizemeal and spices. This they called Chocolatl (choco, cocoa, and latl, water). From the Americans, the Spaniards derived an acquaintance with C., and by them it was introduced into Europe in 1520. C. is used in South America, Spain, and Italy, more than in other parts of the world, although it is used to a considerable extent in Germany. Its use in Britain has given place in a great measure to that of the simpler cocoa.


CHOIR (Lat. chorus). In its literal sense, the C. is the portion of the church devoted to the singers; and in all descriptions which concern the ritual it is so limited, including only the space from the western door or screen to the end of the stalls, whilst the part from the stalls eastward to the highaltar is called the presbytery. But in ordinary language, and even as used by architects, it denotes the entire space which is enclosed for the performance of the principal part of the service. In this sense, it includes the C. proper and the presbytery, and corresponds to the chancel in parish churches. Where the church is cruciform, and the term is confined to the eastern limb, it comes to be entirely different


from the C. in the ritual sense, or the stall-place, which in such a building is commonly situated either under the tower or in the nave. In large churches, the aisle generally runs along each side of the C., and frequently passes across the east end of it; an arrangement which is very common in the larger churches of the continent which have polygonal or semicircular terminations.-C. is also the name given to the singers of the choral service.

CHOIR-SCREEN, or CHOIR-WALL, the screen or wall which divides the choir and presbytery from the side aisles. It is often very richly ornamented. CHOISEUL-AMBOISE, ETIENNE FRANÇOIS, DUC DE, minister of Louis XV., was born June 18, 1719, educated by the Jesuits, and on the completion of his studies, entered the army. He fought bravely in the Austrian Wars of Succession; but only after he had attracted the fancy of the king's mistress, Madame Pompadour, did fortune also really favour him. Through the influence of Madame Pompadour, he was made lieutenant-general in 1748, ambassador to the courts of Rome and Vienna in 1756, and Duc de Choiseul in 1758. C. now became instrumental in bringing about a family league of the Bourbon monarchs in Europe; and in 1763, at the close of the war so disastrous to the French arms, he obtained, by his prudence and dexterity, milder terms for his nation than had been expected. This made him very popular, as did also his successful attempt to overthrow the Jesuits. In 1764, Madame Pompadour died, but the power of C. continued unabated. He conceived, and almost carried out, a plan for the formal emancipation of the Gallican Church from papal influence, paid great attention to the improvement of the army and navy, developed the trade and industry both of the nation and of the colonies, and opened up anew an intercourse with India, whose native princes were assisted by French officers in their endeavours to expel the British from the peninsula. He had spies in every European court, and so ruled all diplomatic and political cabals, that the Empress of Russia, who dreaded him, called him Le Cocher de Europe (The Driver of Europe'). But the rise of Madame Dubarry, who succeeded Madame Pompadour in the royal affections, gradually alienated Louis from his able minister, and in 1770 he retired to his magnificent estate of Chanteloup, where he lived in princely splendour. After the accession of Louis XVI, C. received permission to return to Paris. He was often consulted, but never recovered his official position. He died May 7, 1785.

CHO'KE-CHERRY, a name given to certain nearly allied species of Cherry (q. v.), of the Birdcherry section of the genus or sub-genus, natives of North America, having small fruit in racemes, and the fruit at first rather agreeable, but afterwards astringent in the mouth. Some confusion has long existed as to the different kinds, and their botanical names (Prunus or Cerasus Virginiana, serotina, and borealis) are not more determinate than the popular ones. Perhaps they ought to be regarded as mere varieties rather than distinct species. They have a considerable resemblance to the Portugal Laurel, although the leaves are deciduous. The bark is used as a febrifuge and tonic, under the name of Wild Cherry Bark; and by distilling it with water, a volatile oil is obtained from it associated with hydrocyanic acid, called Oil of Wild Cherry. This bark allays nervous irritation, and is particularly suitable as a first tonic in cases of recovery from fever or inflammation.


CHOKING, the obstruction of the gullet, or of the passage leading to it, by morsels of food imperfectly chewed, or other substances accidentally swallowed. The consequences of C. in the human subject are serious, and will be best considered in connection with the parts concerned. See PHARYNX and ESOPHAGUS. What follows relates to the C. of cattle.

Causes.-These may be classified under two heads: 1. Those that depend on the material swallowed; and 2. Those that depend on the animal swallowing. Under the first head we find sharp-pointed objects which become fixed into or entangled in the membrane lining the throat and gullet; solid masses too large to pass on to the stomach; dry farinaceous materials which clog in the passage. The second class of causes consists in inflammation of the throat, or irritation of the organs of deglutition; constrictions of the passage, as in crib-biting horses; ulceration of the sophagus, which is apt to run after C., and is the cause of a relapse; lastly, without any disease of the deglutating organs, an animal may be choked by eating too greedily, and imperfectly masticating or salivating its food.

Symptoms.-These vary according to the position of the obstruction. If high up in the pharynx, the animal cannot swallow, evinces great distress, and attempts to cough up the object. Saliva drivels from the mouth, the animal chews, and makes an occasional ineffectual effort to swallow. The breathing is very greatly disturbed. In some cases a large lump of food has become fixed in the larynx or upper part of the windpipe, and has suddenly suffocated the animal. When the obstruction is in the course of the gullet down the neck, the symptoms are very similar, though less urgent, and there is additionally the local sign of swelling, with the peculiar hardness or softness of the substance indicating its nature. When an animal is choked by a substance lodging in the gullet within the chest, the symptoms are more mysterious, and likely to mislead. The animal swallows; a considerable quantity of liquid may enter the gullet, but it is suddenly regurgitated or thrown up, as in the act of vomiting. The distress is great; and in the course of three or four days, unless the animal is relieved, it dies of prostration. In the ox, sheep, and goat, the most alarming symptoms, in any case of C., arise from the paunch becoming distended by gas. This condition will be treated under the head HOVEN.

Treatment.-Remove the obstruction with the hand, when you can. Cause the animal to swallow the substance, if possible, by giving it water or oil. Carefully push the offending agent down by a


probang, if it is possible to effect this, and if withdrawal by the mouth is impracticable. In some cases, the gullet has to be cut into by a qualified surgeon. After a case C., keep the animal on soft food, and attend to its general health, in order to avoid a relapse, which is of frequent occurrence in cattle.

CHO'LERA, a Greek term used in the Hippo. cratic writings, but of indeterminate etymology.




being derived perhaps from chole, bile, or from pestilence, too easily recognised by a few leading cholera, a water-spout or gutter. It is now uni- features. After some hours or days of simple relaxversally employed in medicine as indicating one ation of the bowels, vomiting commences, and of two or three forms of disease, characterised by occurs again and again, accompanied by frequent vomiting and purging, followed by great prostration and extremely copious discharges downwards, of strength, amounting in severe cases to fatal at first of matters coloured with bile as usual, but collapse. The variety called cholera sicca (dry C.) in the end of colourless and turbid fluid resemby ancient writers (in which collapse and death take bling water in which rice has been boiled. These place without discharges) is comparatively rarely discharges (often to the extent of gallons of liquid), observed. The milder forms of C. occur almost every succeeding each other with the most alarming summer and autumn, even in temperate latitudes, rapidity, act as a drain upon the fluids of the body and are hence termed by some-in reference to this generally; and by the changes they effect upon the country, and by way of contrast-British or Summer blood, contribute to bring about the state called C.; while the more devastating and fatal forms of collapse. In this condition, the patient lies motionthe disease are generally supposed to originate only less and apathetic, except when tormented by in tropical countries-especially in India-and thence cramps, which are of frequent occurrence; the surto be propagated epidemically over vast populations, face is cold; the finger-ends, lips, and tip of the and in a somewhat regular geographical course, nose become livid; the eyes are deeply sunk in reaching this country usually through Persia, the the sockets, and often bloodshot; the tongue is steppes of Tartary, Russia, and the Baltic, at the clammy; the breath without any sensible warmth same time extending to Egypt, Turkey, and the south when caught on the hand; the pulse is suppressed of Europe. These very fatal forms of the disease are at the wrist, the breathing extremely slow and commonly called Asiatic, Oriental, or Epidemic C.; feeble, the heart just audible through the stethosometimes Cholera Morbus, or Pestilential Cholera. scope. Purging and vomiting have ceased; even The milder forms are sometimes also called Bilious the urinary secretion is dried at its source. C.; and the severer, Spasmodic C., from the character fact, all the vital processes are nearly brought to of the symptoms in each. Some writers of great a stand, and unless reaction comes, a few minutes, authority are inclined to consider the two forms as or at most a few hours, suffice to bring life to a one disease, varying in individual cases and according close. Reaction in the most favourable cases is to season. It is certain that it is not always possible gradual and without accident; it is not unfrequently, to distinguish the one form from the other in parti- however, accompanied by fever, closely resembling cular instances; but the marked difference between typhus, and constituting, at least in the temperate the mortality of groups of cases of British C. on the zone, one of the chief dangers of the progress of one hand, and of Oriental or Asiatic C. on the cholera. other, renders it probable that there is something in the latter disease which amounts to a distinction in kind. Whether in the milder or severer form, C. is usually ushered in by a period of premonitory symptoms, when the more distinctive characters of the disease are not established, the case resembling one of common diarrhoea (q. v.) or looseness of the bowels. At this stage, it is very apt to be neglected, and unfortunately, in the severer epidemic forms of the disease this is the only stage much under control. Whenever, therefore, there is a reasonable suspicion that Epidemic C. is threatened, every person attacked with diarrhoea should make a point of placing himself under medical advice, and, if possible, of escaping from any situation in which epidemic disease is known to be prevalent. He should also be particularly attentive to diet, and especially to the purity of the water he drinks, and to its absolute freedom from contamination by animal matters filtering through the soil, or thrown into water courses by sewers, &c. If water absolutely cannot be had in a pure state, it should be boiled before being used for drink, or indeed for any domestic purpose. Many cases of C., and several local epidemics, have been traced in the most positive manner to organic impurities of the drinking-water; and no single cause of the disease has been established by so much evidence as this. Hence, in all probability, arises the well-known preference of C. for low situations, and particularly for the low-lying flats on the banks of rivers, especially where the inhabitants are supplied with water from streams or wells polluted by sewerage. The researches of the Scientific Commission sent to Egypt during the severe epidemic of 1883, and especially those of Dr Koch in 1884, when Toulon, Marseilles, and later Naples, suffered severely, seem to prove that C. is due to the presence and multiplication in the intestines of a specific bacillus or bacterium (see GERM THEORY, in SUPP., Vol. X.).

Medicine is almost powerless against C., except in the earliest stages, in which the treatment usually pursued in diarrhoea (q. v.) has sometimes been found useful. Very remarkable temporary restorative effects have been found to follow the injec tion into the veins of dilute solutions of saline matter, resembling as nearly as possible the salts of the blood which are drained away in the discharges. Unhappily, these experiments have as yet only very imperfectly succeeded. The patient is restored to life, as it were, from the very brink of the grave; but he revives only for a few hours, to fall back into his former condition.

The true medicine of C., so far as we yet know, is preventive medicine. The measures to be adopted have been partly pointed out above; in addition, it may be said that personal cleanliness is of the first importance; and that all unnecessary contact with the sick should be avoided, as the disease is probably to some extent contagious, though by no means in the highest degree. In short, all the precautions are to be taken which are recommended in the case of Epidemic Disease (q. v.).

CHOLE'STERINE is one of those bodies which are termed by chemists lipoids, or non-saponifiable fats. It was originally discovered in gall-stones, (although occurring in very minute quantity) of bile, but is now recognised as an ordinary constituent blood, and the tissue of the brain. It likewise morbid fluid products. occurs in pus, the contents of cysts, and other

It separates from its solutions in glistening nacreous scales, which, when examined under the microobtuse angles are 100° 30', and whose acute angles scope, appear as very thin rhombic tablets, whose are 79° 30. Different formula have been assigned

The epidemic of 1848-1849 carried off 53,293 persons in England and Wales; and that of 1854, 20,097 persons. The next visitation was in 1866. In Egypt,

We cannot here give a minute description of fully in 1883, the C. carried off 55,000 persons. Probably developed Asiatic C. It is truly an appalling twice as many deaths were not registered.

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