ZIP. This name, written 11 in Ilebrew, occurs only in the first book of Kings, in the 6th chapter, and in the let and 37th verses. It is the mouth now called Jyar. The word is derived by the Jews from a root signifying to be splendid, in reference to the splendour of the season when the month occurs, April and May. The word is found several times with a slight orthographical difference in the book of Daniel, and is usually translated " brightness." [Him.] ZINC (Zn). Speller. A commercial metal which has been known in the metallic state since the time of Paraeelsus. It is never met with in the native state, but is extracted from two ores—calamine, or carbonate of zinc, and blende, or sulphide of zinc. A native oxide of zinc found in New Jersey has also recently been rendered available for the extraction of the metal.
The commercial metal is never pure, though usually sufficiently so for most chemical purposes. The pure metal may be obtained by dissolving common zinc in dilute sulphuric acid, filtering, treating excess of sulphurettod hydrogen, again filtering, and precipitating the boiled filtrate with carbonate of soda. The washed and ignited carbonate must then be distilled in a porcelain retort with charcoal from lump sugar.
Zino is a bluish-white crystalline and hard metal, brittle at 400° Fahr., malleable and ductile between 300' and 200', but again some what brittle at ordinary temperatures. It melts at 773', and boils at a bright red beat estimated by Deville at 1904'. In contact with air the vapour burns with a magnificent greenish-blue flame, forming copious white flocculi of protoxide. At ordinary temperatures zinc gradually oxidises in a moist atmosphere, but the superficial film of oxide preserves the remaining metal for a long time unchanged. It readily dissolves in dilute mineral acids, and in concentrated solutions of potash and soda. It also combines with chlorine, iodine, and bromine at ordinary temperatures. The equivalent of zinc is 321, and its specific gravity to The following are the principal compounds of zinc :— Oxide or Protoxide of Zinc (Zn0), Zinc-white.—This is the oxide which exists in the native carbonate. It may be prepared in various modes : first, by merely igniting the metal in contact with air; in this case combustion takes place readily. and a light white compound is formed, which was called by the old chemists by the various names of nihil album, Lana philosophica, pomptolix, and flowers qj zinc.
Oxide of zinc may also be procured by dissolving the metal in a dilute acid, either the sulphuric, nitric, or hydrochloric, and decom posing the solution by a carbonated fixed alkali ; carbouate is first precipitated, but this, when heated, loses its carbonic acid, and the oxide is obtained as a yellowish powder.
In the manufacture of brass an impure oxide of zinc condenses in the flues of the furnaces and is sold under the name of tatty.
The properties of oxide of zinc are,—that it is inodorous, insipid, insoluble in water, and infusible by heat; it combines readily with adds, and also with the alkalies ammonia, potash, and sods. So that when it is precipitated by them, they redissolve it if added in excess. It is the basis of all the oxisalts of zinc.
Peroxide of Zinc, probably a binoxide (ZnO, I), is obtained by taking gelatinous hydrate of zinc, and pouring upon it an aqueous solution of binoxide of hydrogen (oxygenated water), containing about eight times its volume of oxygen gas, and shaking the mixture thoroughly ; the peroxide of zinc resulting from this operation is white, inodorous, insipid, and decomposes spontaneously when kept moist or when heated. It is also decomposed by acids, which dissolve protoxide of zinc and reproduce binoxide of hydrogen.
Chloride of Zinc (ZnCI) may be formed by the direct action and combination of these elements. When zinc filings are thrown into chlorine gas, heat and light are evolved, owing to their combination ; it is more readily prepared by dissolving oxide, or still better metallic zinc, in hydrochloric acid, and evaporating to dryness ; or by heating the metal in a tube through which dry hydrochloric acid gas is transmitted.
The properties of chloride of zinc are,—that it is colourless, has a very styptic taste, is readily soluble in water, and crystallises from it with difficulty; It is very volatile at a red heat. It was formerly called butter of :inc.
Bromide of Zinc (ZnBr) is formed by passing bromine in vapour over zinc heated to redness; or it may be obtained in solution by agitating a mixture of these elements and water : the solution is colourless, and when evaporated till a pellicle is formed, it becomes a crystalline mass on cooling.
This bromide has a sweetish, astringent taste, and is very deli quescent; it becomes dry when heated, and fuses at a red heat.