184 ANTIMONY. I 



China for the current coin, and for that purpose is employed j 



in the utmost purity. When zinc is heated it readily attracts ' 



oxygen ; and at a white heat, the absorption of oxygen is so I 



rapid and violent, that the oxyd immediately sublimes, and ; 



for this reason it has acquired the name of flowers of zinc, i 



It is frequently combined with copper or tin, in various pro- '■ 



portions, and these Thixtures constitute some of the most ; 



useful compound metals. It is used in medicine, is the base '•■ 



of white vitriol, and its carbonate or oxyd may be advanta- ] 

 geously substituted for white lead in house-painting. 



Manganese is a brilliant metal, of a darkish white colour, 



inclining to gray, of considerable hardness, and of difficult fu- I 



sibility. When exposed to the air, it absorbs oxygen with | 



rapidity and falls into powder. It abounds in this country ; l 



but on account of its great affinity for oxygen, it has never i 



been discovered in a metallic state. Its oxyd is easily pro- vj 



cured ; but the pure metal can only be obtained by art, and -4 



in order to preserve specimens of it, it is necessary to var- \ 



nish them, or to keep them immersed in oil, or ardent spirits. 1 



Its oxyds are used in preparing the bleaching liquor, in pu- i 



rifying glass, and in glazing black earthen ware. It is also ] 



employed, in some cases, to give colours to enamels in the ; 



manufacture of porcelain. The black oxyd is much used by  



chemists for producing oxygen gas, which, by the applica- ' 



tion of a red heat, it yields in great abundance. ] 



Antimony is a brilliant, brittle metal, of a silvery white 



colour, which has not much tenacity, and is entirely desti- j 



tute of ductility. It may be entirely volatilized by heat. It ' 



is also susceptible of vitrification, and produces a hyacinth- j 

 coloured glass. Antimony is combined with some other 



metals in making types for printers. Its oxyds are employ- J 



ed in medicine, and in colouring glass. \ 



Arsenic is generally found in combination with sulphur, * 



oxygen, and many of the metals. Its colour is bluish, or ] 



greenish white, becoming, on exposure to the air, dark, \ 



almost black ; it is extremely brittle, and at the same time \ 



the softest of all metals. It is one of the most active of mi- [ 



neral poisons. * 



Beautiful shades of various colours may be given to diflfe- y 



rent substances by solutions of arsenic. So that the sub- I 



stance which is most injurious to the animal economy, ap- j| 



pears to be endowed with properties for embellishing the J 



