CHEMISTRY. 



Element! 



of 

 Chemistry. 



Cofn- 



with iora- 

 buslibles. 



a solution of carbonate of potash. Then wash and 

 dry it. The protoxide thus obtained is a dirty white 

 po-.vd.T. At a moderate red heat, it melts, and be- 

 comes opake, and crystallizes in needles on cooling. 

 It is composed of 81.5 antimony, 18.5 oxygen. 



The peroxide may be obtained by keeping the an- 

 timony in a red heat ; for the argentine flowers are 

 peroxide of antimony. It may be obtained also by 

 dissolving antimony in nitric acid, or by throwing it 

 into red hot nitre. It is white, insoluble in water, 

 and less soluble in acids than protoxide. It is easily 

 volatilized by heat, but requires a pretty high tem- 

 perature for fusion. It is composed of 77 antimony, 

 and 23 oxygen. 



3. Antimony has never been combined with hy- 

 drogen or carbon ; but it unites readily to phospho- 

 rus and sulphur. 



Phosphuret of antimony may be formed by drop- 

 ping bits of phosphorus into melted antimony. It 

 is white, brittle, and appears of a laminated struc- 

 ture. 



Sulphuret of antimony exists native, and was for- 

 merly distinguished by the name of antimony, the 

 pure metal being called regtilm of antimony. It has 

 a dark-bluish grey colour, and the metallic lustre. 

 It is brittle, and often crystallized. It is composed 

 of 75 antimony and 25 sulphur. 



The protoxide of antimony has the property of 

 dissolving different portions of the sulphurct by 

 means of heat, and forming with it a vitreous sub- 

 stance of a reddish brown colour, and differing in 

 transparency according to the proportion of sulphu- 

 ret. It is called glast of antimony, crocus metal- 

 lurum, liver of antimony, according to its appear- 

 ance. 



4. Antimony does not combine with the simple 

 incorobustibles. But it forms alloys with almost all 

 the metals. It renders other metals brittle, and none 

 of its alloys is of much consequence, except the al- 

 loy of tin and antimony, which constitutes rttrtcr ; 

 and of lead and antimony, which constitutes the me- 

 tal of printers types. 



SECT. XVII. Of Tellurium. 



Tellurium. This metal has been hitherto found only in the 

 mine of Mariahilf in Transylvania. Its peculiar na- 

 ture was first suspected by Mtiller of Reichengtein 

 in 1782, and fully proved by the experiments of Kla- 

 proth in I- '.<*. 



Properties ], I[ S colour is bluish white, its texture laminat- 

 ed, and its brilliancy considerable. It is very brittle. 

 Its specific gravity is 6.115. It melts a little above 

 the melting point of lead, aud may be easily distil- 

 led over in close vessels. When cooled slowly it 

 crystallizes. 



Oxide*. 2. When exposed to the blowpipe on charcoal, it 



burns with a blue flame, and is converted into awhile 

 oxide, which disperses in smoke. The same oxide 

 may be obtained by dissolving the tellurium in muri- 

 atic acid, and diluting with water. When heated, it 

 m Its into a straw-c., loured mass. 



3. Tellurium may be combined with sulphur by 

 funon. The suljihuret has a leaden grey colour and 

 radiated texture. Mr Davy has lately discovered 



Ktemeiits 



try. 



Alloys. 



that tellurium combines readily with hydrogen, and 



forms a gas soluble in water, and possessing, like 



j u j u -i Chemisi 



sulphureted hydrogen, the characters of a weak acid. v _ 



The action of the other simple combustibles has not 

 been tried. 



4. It may be amalgamated with merqury ; but we 

 are ignorant of the metallic alloys which it is capable 

 of forming. 



SECT. XVIII. Of Arsenic. 



The ancients gave the name of arsenic to a com- Arsenic- 

 pound of arsenic and sulphur. The while oxide of 

 arsenic, known in commerce by the name of arsenic t 

 must also have been known to them. But they do 

 not seem to have been acquainted with the substance 

 which we call arsenic in its metallic state. The dis- 

 coverer of this substance is unknown. But Brandt 

 first ascertained its properties, in 1733. 



1. Arsenic has a bluish white colour, and a good Properties. 

 deal of brilliancy. When heated in the open air, it 

 blackens, smokes, and emits the odour of garlic. It 



is the softest metal known. Its specific gravity is 

 8.31. It is remarkably brittle. It is very volatile, 

 subliming without melting when heated to 356. 

 When slowly sublimed, it crystallizes in tetrahe- 

 drons. 



2. It may be kept under water without alteration, Oxides, 

 but in the open air it soon falls into a black pow- 



der. We know two oxides which it is capable of 

 forming. 



The while oxide is obtained by exposing arsenic 

 to a moderate heat. The metal takes fire, emits the 

 smell of garlic, and is volatilized in a white smoke, 

 which is the oxide in question. It is obtained in the 

 large way during the smelting of various ores which 

 contain arsenic. It is white, compact, and like glass. 

 Its taste is acrid and sweet, and it is one of the most 

 virulent poisons known. It dissolves in water, and 

 exhibits different properties of an acid. It dissolves 

 also in alcohol, and in oils. It crystallizes in tetra- 

 hedrons. It sublimes at the heat of 383. Its spe- 

 cific gravity varies from 3.7 to 5.000 according to 

 its state. It is composed of 75.2 arsenic, and 24.8 

 oxygen. 



The peroxide of arsenic was discovered by Scheele. 

 It is usually called arsenic acid. It may be obtain- 

 ed by dissolving white oxide of arsenic in nitro-mu- 

 riatic acid, evaporating to dryness, and applying 

 sufficient heat to drive off these acids. In this state 

 it is a white mass, which readily dissolves in water. 

 Its taste is excessively sour, and it possesses all the 

 other properties of an acid. It is composed of 65.4 

 parts of arsenic and 34.6 of oxygen. 



3. Arsenic combines readily with the simple com- Com. 

 bustibles, carbon excepted, with which it has not P" nds 



hitherto been united. 



r . . , . 



When a mixture of tin and arsenic, or of zinc and 



arsenic, is dissolved in muriatic acid, the hydrogen 

 which '-shales holds a considerable portion of arsenic 

 in solution, and is known by the name of arsenical 

 hydrogen. This gas possesses some curious proper- 

 ties, which haxe been investigated by Trommbdorff 

 and Stromeyer. 



Phosphuret of arsenic may be formed by mixing 



with com. 



