Page:Encyclopædia Britannica, Ninth Edition, v. 5.djvu/690

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676
CHI—CHL

CHIUSA, or La Chiusa, a town of Italy on the Pesio, in the province of Curieo, and about ten miles south-east of the city of that name. It has a population of upwards of 0000, chiefly engaged in the manufacture of silk and glass. It is not to be confounded with a hamlet in the province of Turin, which was named Chiusa (enclosure) from its position near the fortified line erected by Desiderius of Lombardy, in 774, to check the advance of Charlemagne.

CHIUSI, a town of Italy, in the Tuscan province of Siena, situated on a hill, and not far from the Lake of Cluusi. It is a bishop s see, and has a large cathedral, but is chiefly interesting for the Etruscan bronzes, mirrors, va> .., and funereal urns found in the vicinity, of which its museums contain collections. Chiusi, the Clusium of the Romans, was one of the twelve cities of the Etruscan confederation, and was the headquarters of Porsena. After the decay of the Roman power it sank in importance, and in the Middle Ages malaria greatly reduced the number of its inhabitants ; of late years, however, the prospects of the place have greatly improved, in consequence of the drainage of the marshes in the neighbourhood. Population, G460.

CHIVASSO, a city of Italy, in the province of Turin, at a railway junction, 1 5 miles north-east of the city of Turin. Situated on the left bank of the Po near the influx of the Oreo, it was formerly considered the key of Piedmont ; but its fortifications were dismantled by the French in 1804, and it is now only enclosed by a single wall with two gates leading to two suburbs. The front of the church of San Pietro, a building of the loth century, is decorated with ornaments and entire statues in terra cotta, of great elegance, but much defaced. Of the ancient palace of tbe counts of Montferrat an octagonal tower still remains. The principal trade of the town is in grain and wool ; and its lampreys are in repute. On the opposite side of the Po, and a few miles down the stream, are the ruins of the Roman city of Industria, which were discovered in 1745. Population, 7800.

CHLAMYDOPHORE (Chlamydophorus truncatus), an Edentate Mammal found at Meudoza, on the eastern slope of the Cordilleras, where it is known as the Pichiciago, but is so seldom seen as to be regarded with curiosity even by the natives. Its total length is from 5 to 6 inches, and its upper surface is covered with a flexible cuirass somewhat resembling the external armature of the Armadilloes its nearest allies but differing from the latter in being attached only by the middle of the back and the top of the head, the frontal bone of the skull being provided with two prominent knobs for this purpose. The dorsal shield, which contains 24 rows of square, cubical, or rhomboidal plates of a leathery texture, makes, at its posterior edge, an abrupt bend downwards, and is continued to the extremity of the tail, thus forming a posterior shield for the protec tion of the creature s hindquarters while it is burrowing. The sides of the back beneath the shield, the under part of the body, and the limbs are covered with silky hair, of a dirty white colour, longer and finer than that of the mole. An examination of the Pichiciago skeleton proves it to be an exceedingly aberrant member of the Armadillo family, having structural affinities with other and widely different mammals. Thus it resembles the beaver in its flattened paddle-like tail, the mole in its short strong legs and powerful claws, the sloth in its teeth, and ruminants in the form of the lower jaw. It also resembles the ornitho- rhynchus and echidna the lowest mammalian forms in points wherein all three show affinity with birds ; while in the form of the skull and pelvis it is unique among mammals. According to Dr Buckland it makes the nearest approach of living Edentata to the gigantic extinct Megatherium, It is a burrowing animal, living like the mole in the subter ranean galleries which it scoops out with its sharp,, powerful claws, assisted probably by the flattened tail, which is supplied with strong muscles, and thus well adapted for throwing out the earth which gradually accumulates under the creature. Like the mole its ears and eyes are exceedingly small and almost hidden by the long silky hair surrounding them. Another species has recently been discovered in Bolivia somewhat larger than the preceding, and differing from it in having the dorsal shield attached all over to the skin of the back.

CHLORAL, Trichloraldehyde, or Hydride of Trichloracetyl, C 2 C1 3 OH or CClg.COH, a substance dis covered by Liebig in 1832, and further studied by Dumas and Stadeler. It is a heavy, oily, and colourleoS liquid, of specific gravity 1/518 at C., and boiling point 94 0< 4 C. It has a greasy, somewhat bitter taste, and gives off a vapour at ordinary temperature which has a pungent odour and an irritating effect on the eyes, The word chloral is derived from the first syllables of chlorine and alcohol, the names of the substances employed for its preparation. Chloral is soluble in alcohol and ether, in less than its own weight of water, and in four times its weight of chloroform ; it absorbs but is not acted upon by chlorine, and dissolves bromine, iodine, phosphorus, and sulphur. Chloral deli quesces in the air, and, like aldehyde, is converted by water into a hydrate, with evolution of heat ; it combines also with ethylic alcohol and its homologues, and the derived mercaptans. An ammoniacal solution of nitrate of silver is reduced by chloral ; sulphites of the alkalies form with it crystalline compounds ; and nascent hydrogen, by replacing its three atoms of chlorine, converts it into aldehyde (Personne, Ann. Ch. Pharm., clvii. 113). By means of phosphorus pentachloricle, chlorine can be substi tuted for the oxygen of chloral, the body CC1 3 .CC1.,H being produced ; an analogous compound, CC1 V C( C 6 H 5 ) 2 H, containing the radicle phenyl in the place of the oxygen, is obtained by treating chloral with benzene and sulphuric acid. With an alkali, chloral gives chloroform and a formate of the base according to the reaction CC L.COII + KHO ? CC1 3 H + H.CO(OK) ; it is converted by oxidiz ing agents into trichloracetic acid CC1 3 .CO(OH) ; and forms with cyanic acid the body C 5 H 3 Cl G NOo ? (CCL.COH)., COHN. When kept for some days, as also when placed in contact with sulphuric acid or a very small quantity of water, chloral undergoes spontaneous change into the polymeride metachloral, C G H 3 C1 O 3 ? (C.,C1. ; OH). ; , a white porcelaneous body, slowly volatile in the air, insoluble in water, alcohol, and ether, and reconverted into chloral without melting at 180 C.

Chloral is prepared by passing dry chlorine into absolute

alcohol ; the latter must be cooled at first, but towards the end of the operation has to be heated nearly to boiling. The alcohol becomes converted finally into a syrupy fluid, from which chloral is procured by treatment with sulphuric acid. The action of chlorine upon alcohol is complex ; first aldehyde, CH .COH, is produced, which combines with alcohol to form acetal, CH 3 .CH(OC 2 H 5 ) 2 ; this, acted on by chlorine, yields trichloracetal, CCl 3 .CH(OCoH 5 ).,, which is converted by the hydrochloric acid present into chloral alcoholate, CCl 3 .CH.OH.OC 2 H rj , and monochlor- ethane, C 9 H 5 C1. The latter body is also formed directly from alcohol, in the process for the manufacture of chloral, and combines with aldehyde, giving rnonochlorinated ethylic ether, CH 3 CHC1.OC 2 H 5 , which is converted by chlorine into tetrachlorinated ether, CCl 3 .CHCl.OC 2 IIr,. By the action of sulphuric acid, chloral alcoholate and tetrachlorinated ether are resolved into alcohol and chloral, and monochlorethane and chloral, respectively. The crude chloral is distilled over lime, and is purified by

further treatment with sulphuric acid, and by redistillation.