30 мо CHLORINE-CHLOROFORM. 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 constantly 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 40 potassium placed on a 50 white plate; and whenever the iron solution 60 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 1 10 120 20 30 40 40 50 50 60 60 70 70 80 180 80 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. 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 24 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. bling the gas in colour, odour, and other properties. The principal properties of C. are those of a bleacher of cotton and linen (see BLEACHING), and a most 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 quantity, 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. It belongs to the metamorphic rocks, and is often found graduating into gneiss and clay-slate. CHLO'ROFORM, or the TERCHLORIDE OF FO'RMYLE (C,HCl), 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. C. is a highly limpid, mobile, colourless liquid, which is very volatile, has a characteristic and pleasant odour, and an agreeable sweetish taste. It has a specific gravity of nearly 1500 (water = 1000), being thus half as heavy again as water, and boils at 140° F. It is not inflammable in the ordinary sense of the term, as it will not take fire CHLOPICKI-CHLORIMETRY. 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 destitute of sutures; there are resemblances to the manner from those of the mole. Chlamyphorus. The skull is osteology of birds in the ribs and their union to the earth in excavations. Cracow, and withdrew altogether from public life. CHLO'RAL (C,C1,HO2) is a body formed when odour. natural order of CHLO'RIC ACID (CIO) is a compound of one CHLOPICKI, JOSEPH, a Polish general, and 310 30 40 CHLORINE CHLOROFORM. into 100 parts, and water added till the solution 120 30 40 40 50 50 60 70 70 80 80 90 90 60 3 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 quantity, by producing a sensation of warmth in the respiratory passages, and increasing the expectoration; 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. CHLORITE (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 tale. 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. It belongs to the metamorphic rocks, and is often found graduating into gneiss and clay-slate. 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. CHLOROFORM, or the TERCHLO'RIDE OF In nature it is always found in a state of com- FORMYLE (C,HCI,), was originally discovered bination. United with sodium (Na), it occurs very by Soubeiran, and experimented upon by Dumas, largely as the chloride of sodium (NaCl)-common and was long known only to scientific chemists as salt in the ocean; in large beds, as rock-salt; a rare organic body, possessing interest from being in all natural waters, including even rain-water; one of a series of organic substances, but not known in clays, soils, limestone; in volcanic incrustations; to possess any properties likely to call it into use, or and in the vegetable and animal kingdoms. The even likely to let it be known by name to the preparation of gaseous C. by its liberation, directly general public. The remarkable power, however, or indirectly, from common salt, has been fully which it possesses of producing anesthesia, has described under BLEACHING POWDER, which is the led to the preparation of C. on a very extensive form in which C. is prepared and employed com- scale. The materials employed are alcohol, water, mercially. For experimental purposes, the gas may and bleaching powder, and the proportions are four be received in jars filled with water at the pneu- parts of bleaching powder, to which sufficient water matic trough, when the C. rises into the jar, and is added to make a thin paste, and thereafter one displaces the water. When thus obtained, it is a part of spirits of wine; the whole is introduced yellowish-green gas with a peculiar and suffocating into a capacious retort, which must not be more than odour, is not combustible, and a very feeble sup- half filled, and heat being applied, the C., accomporter of ordinary combustion. A lighted candle panied by water and a little alcohol, distils over. placed in it burns with a very smoky flame, owing As the C. is heavier than water, and is not readily to the hydrogen of the oil alone burning, and the miscible therewith, two layers of liquid are obtained carbon being liberated. Several of the metals, such in the receiver-the upper being water and alcohol, as antimony, copper, and arsenic, in a fine state of and the lower being chloroform. The upper liquid division, or in the condition of thin leaves, at once being cautiously poured off, the C. is agitated with become red hot, and burn when introduced into fused carbonate of potash, which abstracts the the gas. A piece of thin paper soaked in turpentine remaining traces of water, and on subsequent likewise bursta into flame. C. has the symbol Cl, redistillation the C. is obtained pure and ready for the atomic weight or equivalent of 355. It use. very heavy gas, nearly 24 tir Mavier than ,ita specific gravity 2470 soluble in of C. in on bling the The C. is a highly limpid, mobile, colourless liquid, it is which is volatile, has a characteristic and mes plea m It an agreeable sweetish taste. vity of nearly 1500 (water= If as heavy again as water, It is not inflammable in the erm, as it will not take fire CHLOROPHYLL-CHOIR. 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 in 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. 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 ANÆSTHESIA; 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 the safest of all anesthetics, 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. CHLO'ROPS. See CORN-FLY and WHEAT-FLY. 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 ship-board to aid in the support of various articles. CHOCKS are pieces of wood employed on 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. CHOCOLATE ROOT. See GEUM. 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 CHOIR-SCREEN-CHOLERA. from the C. in the ritual sense, or the stall-place, CHOKING, the obstruction of the gullet, or of 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. the passage leading to it, by morsels of food imper- heads CHOIR-SCREEN, or CHOIR-WALL, the screen 1. Those that depend on the material or wall which divides the choir and presbytery from swallowed; and 2. Those that depend on the the side aisles. It is often very richly ornamented. animal swallowing. Under the first head we find sharp-pointed objects which become fixed into or CHOISEUL-AMBOISE, ETIENNE FRANÇOIS, DUC DE, minister of Louis XV., was born June entangled in the membrane lining the throat and gullet; solid masses too large to pass on to the 18, 1719, educated by the Jesuits, and on the stomach; dry farinaceous materials which clog in completion of his studies, entered the army. He the passage. The second class of causes consists fought bravely in the Austrian Wars of Succes-in inflammation of the throat, or irritation of the sion; but only after he had attracted the fancy organs of deglutition; constrictions of the passage, of the king's mistress, Madame Pompadour, did as in crib-biting horses; ulceration of the sofortune also really favour him. Through the phagus, which is apt to run after C., and is the influence of Madame Pompadour, he was made cause of a relapse; lastly, without any disease of lieutenant-general in 1748, ambassador to the the deglutating organs, an animal may be choked courts of Rome and Vienna in 1756, and Duc de by eating too greedily, and imperfectly masticating or salivating its food. Choiseul in 1758. C. now became instrumental in CHOKE-CHERRY, a name given to certain of the obstruction. If high up in the pharynx, the Symptoms.-These vary according to the position 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 HOVE. 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. In probang, if it is possible to effect this, and if CHO'LERA, a Greek term used in the Hippocratic writings, but of indeterminate etymology, |