=Chlorate of Potassa.= Chlorate of potassa is formed by passing a current of chlorine, in excess, through lime-water, and then treating the mixture with the chloride of potassium or by the carbonate or sulphate of potassa. The chlorate of potassa and chloride of calcium are formed,--the former crystallizes, the latter remains in solution. It is soluble in water, but not sensibly so in alcohol. It is a more powerful oxidizing agent than nitre, and, when mixed with a combustible body, easily explodes by shock or friction. It is inflamed by simple contact with sulphuric acid, and thus affords a simple means of exploding mines. =Chlorates.= Oxidizing agents used in _explosives_ (which see). Chlorate of potassa is the salt ordinarily used. =Chocks.= See IMPLEMENTS. =Choctaw Indians.= A tribe of aborigines which formerly lived in Mississippi, along the Yazoo River. They are now settled in Indian Territory, and are partially civilized. See INDIANS AND THEIR AGENCIES. =Choczim=, or =Chotyn=. A fortified town of Bessarabia, Southern Russia, on the Dniester. Here the Turks were defeated by the Poles in 1621, and again in 1673; the Turks were again defeated at this place by the Russians in 1739. =Choke.= The tied end of a cartridge; also the constriction of a rocket-case, etc. =Choker.= An implement used by engineers to compress and test the circumference of a fascine. It consists of two strong pieces of wood about 4 feet long joined by a chain. Two rings inserted in the chain mark the length of the circumference required. =Chokey.= An East Indian guard-house and prison. =Cholet.= A town of France, in the department of Maine-et-Loire. Here, during the Vendean war, two actions were fought in 1793, in both of which the royalists were defeated. In the first they lost their brave general, Bonchamps; and the second drove them across the Loire, thus virtually deciding the war against them. =Chosroes.= See KHOSROO. =Chotyn.= See CHOCZIM. =Chouans.= The name which a band of peasants received who fought for the monarchy against the convention in Maine and Normandy in 1793. They received their name from their leader, Jean Cattereau, nicknamed “Chouan,” and were with great difficulty subdued, their final submission not taking place till 1803. =Christian Charity, Knights of the Order of.= Was the name of an order instituted by King Henry III. of France for the support of maimed officers and soldiers who had done good service in the wars. Henry IV. placed it under the charge of the marshals and colonels of France, and by means of it many of those who had served their country faithfully were enabled to spend the latter portion of their lives in peace and above want. The order formed the germ of that noble hospital, the _Invalides_, which was founded by Louis XIV., and which served as a model for the English hospitals of Greenwich and Chelsea. On the founding of the hospital the order was superseded.