ZIMMERMANN ZINC. 



173 



himself in a prosecution for libel, for a charge which 

 lie brought against the baron de Knigge, for an tin- 

 avowed publication. While his mind was in a state 

 of agitation from these causes, the approach of the 

 French towards Hanover, in 1794, almost subverted 

 his reason. He could think of nothing but the pil- 

 lage of bis house and ruin of his fortune, and, under 

 this morbid irritation, wasted to a skeleton, and 

 died, absolutely worn out, in 1795, at the age of 

 sixty. Most of his works have been translated into 

 English ; and his Solitude was, at one time, very 

 popular. His writings towards the end of his life 

 almost destroyed the reputation which he had earn- 

 ed at an earlier period. 



ZIMMERMANN, EBERHARD AUGUSTUS WIL- 

 LIAM VON, a German writer of note in the depart- 

 ments of geography, ethnography, anthropology and 

 zoology, was born, in 1743, at Uelzen, near Celle, 

 in Hanover. He studied at Gb'ttingen, where he 

 wrote on the analysis of curves, and at Leyden, 

 where he conceived the idea of dividing the animal 

 kingdom with reference to climates, and of direct- 

 ing his attention to the migrations and the ramifi- 

 cations of the races, beginning with man himself 

 an idea which he kept in view in all his travels and 

 in his writings. He visited England, Italy, France, 

 also Russia and Sweden. To England he went 

 three times, and published in London, in 1788, a 

 Political Survey of the present State of Europe, 

 with sixteen statistical tables. In 1797, he pub- 

 lished General Observations on Italy, also a treatise 

 on the Molfetta in Apulia. His Geographical 

 Annals were continued for three years. In 1795 

 appeared his France and the Free States of North 

 America, and, at a later period, his General View 

 of France, from Francis I. to Louis XVI., and of 

 the Free States of North America (1800, 2 vols.). 

 In 1766, he had been appointed professor of natural 

 philosophy in the Caroline college at Brunswick. 

 The emperor Leopold raised him to the rank of no- 

 bility for his writings against the spirit, of the revo- 

 .ution. His most important work is his Geographi- 

 cal Pocket-book, which appeared in twelve annual 

 numbers, from 1802 to 1813, and describes, in an 

 agreeable manner, a great part of the earth. A sort 

 of abridgment appeared under the title the Earth 

 and its Inhabitants, according to the latest Dis- 

 coveries, in five volumes. In 1779, he wrote on 

 the compressibility and elasticity of water. He 

 died in 1815. 



ZINC, is a metal of a bluish-white colour, some- 

 what brighter than lead, of considerable hardness, 

 and so malleable as not to be broken with the ham- 

 mer, though incapable of much extension in this 

 way. At a temperature between 212 and 300 

 Fahr., it is both malleable and ductile. Its specific 

 gravity is from 6-9 to 7'2. When broken by bend- 

 ing, its texture is seen to be coarsely granular. On 

 account of its imperfect malleability, it is difficult 

 to reduce it into small parts by filing or hammering ; 

 "but it may be granulated, like the malleable metals, 

 by pouring it, when fused, into cold water ; or, if 

 it be heated nearly to melting, it is then sufficiently 

 brittle to be pulverized. It melts at about 700 

 Fahrenheit, and soon afterwards becomes red hot, 

 burning with a dazzling white flame of a bluish or 

 yellowish tinge, and is oxidized with such rapidity 

 that it flies up in the form of white flowers, which 

 are called fioti-ers of zinc, or philosophical wool. 

 These are generated with such rapidity that the 

 access of air is soon intercepted, and the combus- 

 tion ceases unless the metal be stirred, and a con- 



siderable heat kept up. If the metal be heated in 

 close vessels, it rises without being converted into 

 oxide. Chemists are not agreed as to the number 

 of oxides of zinc: but the one above mentioned is 

 the only one of importance. At common tempera- 

 tures, it is white ; but when heated to low redness, 

 it assumes a yellow colour, which gradually disap- 

 pears on cooling. It is quite fixed in the tire, and 

 insoluble in water. It is a strong salifiable base, 

 forming regular salts with acids, most of which are 

 colourless. It combines also with some of the al- 

 kalies. It consists of thirty-four parts zinc and 

 eight parts oxygen. When metallic zinc is exposed 

 for some time to air and water, or is kept under water, 

 it acquires a superficial coating of a gray matter, 

 which is called a sub-oxide of zinc. When zinc is 

 burned in chlorine, a solid substance is formed, of 

 a grayish-white colour, semi-transparent. This is 

 the chloride of zinc. It may likewise be made by 

 heating together zinc filings and corrosive sublimate. 

 It is soft as wax, fuses at a temperature a little above 

 212 Fahr., and rises in the gaseous form at a heat 

 much below ignition. Its taste is intensely acrid, 

 and it corrodes the skin. It acts upon water, and 

 dissolves in it, producing much heat. Its solution, 

 decomposed by an alkali, affords the white hydrated 

 oxide of zinc. This chloride has been called the 

 butter of zinc and muriate of zinc. It consists of 

 nearly equal weights of zinc and chlorine. Bro- 

 mide and iodide of zinc may be formed by processes 

 similar to those for preparing the analogous com- 

 pounds of other metals. Sulphuret of zinc may be 

 formed by heating to redness a mixture of oxide of 

 zinc and sulphur. This substance, as found in na- 

 ture, will be described in the sequel, under the 

 head of the ores of zinc. The salts of zinc possess 

 the following general properties : They generally 

 yield colourless solutions with water ; ferroprussi- 

 ate of potash, sulphureted hydrogen and alkalies, 

 occasion white precipitates ; infusion of galls pro- 

 duces no precipitate. 



Sulphate of zinc. Dilute sulphuric acid dissolves 

 zinc, and the salt may be obtained in fine prismatic 

 four-sided crystals. It is commonly called white 

 vitriol. It may be formed also by dissolving the 

 white oxide of zinc in sulphuric acid. But it is 

 more extensively manufactured from the native 

 sulphuret in the following manner : The ore is 

 roasted, wetted with water, and exposed to the 

 air. The sulphur attracts oxygerr, and is converted 

 into sulphuric acid ; and the metal, at the same time 

 being oxidated, combines with the acid. After 

 some time, the sulphate is extracted by solution in 

 water; and by evaporating the solution to dryness, 

 the mass is run into moulds. The taste of this 

 salt is extremely styptic. It reddens vegetable 

 blues, though in composition it is strictly a neutral 

 salt. Dilute nitric acid combines rapidly with zinc, 

 and produces much heat, at the same time that a 

 large quantity of nitrous acid gas is evolved. The 

 solution is very caustic, and affords crystals by 

 evaporation of nitrate of zinc. Muriatic acid acts 

 very strongly upon zinc, and disengages much 

 hydrogen. Phosphoric acid also dissolves this 

 metal. The phosphate does not crystallize, but 

 becomes gelatinous, and may be fused by a strong 

 heat. Fluoric, boracic, carbonic, acetic and oxalic 

 acids, each form compounds with the oxide of zinc. 

 Zinc may be combined with phosphorus by project- 

 ing small pieces of phosphorus on melted zinc. 

 The compound is white, with a shade of bluish- 

 gray. Zinc forms a brittle alloy with antimony. 



