ANTIMONY 199 



charcoal powder, from 65 to 70 parts of metallic antimony or rogulus should bo 

 obtained. Glauber salts may bo used advantageously instead of soda. Another for- 

 mula is, 100 parts of sulphide of antimony, 42 of metallic iron, and 10 of dry sulphate 

 of soda. The product thence is said to be from 60 to 64 parts of metal. 



In the works where antimonial ores are smelted, by means of tartar (argol, 

 bitartrate of potash), the alkaline scoriae which cover the. metallic ingots are not 

 rejected as useless, for they hold a certain quantity of antimonial oxide in combination 

 a property of the potash flux which is propitious to the purity of the metal. These 

 scoriae, consisting of sulphide of potassium and antimonate of potash, being treated 

 with water, undergo a reciprocal decomposition ; the elements of the water act on 

 those of the sulphide, and the resulting alkaline hydrosulphide reacts on the 

 antimonial solution so as to form a species of kermes mineral, which precipitates. 

 This is dried, and sold at a low price as a veterinary medicine under the name of 

 kermes, by the dry way. 



Metallic antimony is now largely obtained from the native sulphide by the reducing 

 action of iron. A quantity of scrap-iron or of tin-plate clippings is thrust into the 

 molten sulphide, previously separated from the gangue, and the antimony is thus 

 reduced, with formation of a regulus of protosulphide of iron (ferrous sulphide). The 

 process of smelting antimony by means of iron resolves itself into three distinct 

 operations, which may be thus described : ' 



1. Singling. A charge of about 40 Ibs. of the ore, broken up into pieces each 

 about half the size of an egg, is introduced into a red-hot crucible, with a quantity of 

 slag obtained in the operation of doubling at a previous smelting. Above this ore 

 and slag is placed a mass of refuse iron, consisting generally of tin-plate in the form 

 of old kettles and saxicepans, and beaten for convenience' sake into the shape of a 

 cone. Assuming that the ore contains from 50 to 55 per cent, of antimony, about 20 

 Ibs. of iron would be added to the quantity of ore and slag specified above. When 

 the charge has melted, the iron cone is pressed into the molten mass, and the reduction 

 thus effected by action of the metal on the fused sulphide. The crucible is then 

 removed from the fire, and the contents poured into a large conical cast-iron mould. 

 On the cooling of the mass, a button of crude antimony is found below the regulus, 

 from which it is readily separated by a tap with the hammer. 



2. Doubling. The ' singles,' or buttons of metallic antimony from the first melting 

 are sorted, so that those which contain an excess of sulphur may bo melted with 

 those which have an excess of iron. Seventy or eighty pounds of these sorted singles 

 are put into a crucible with a little salt-cake (crude sulphate of soda) and melted. 

 This re-melted antimony is then poured" into a cast-iron bowl, where it solidifies, and 

 forms the product known as ' bowl metal.' 



3. Refining or Frenching. A charge of from 60 to 70 Ibs. of bowl metal is intro- 

 duced into a red-hot crucible, with a pound or two of American potash and about 10 

 Ibs. of slag from the previous refining. When melted, the mass is stirred with an 

 iron bar, and the character of the slag adhering to the stirrer enables the workman to 

 judge whether the refining be complete or no. The refined metal is poured into 

 moulds, where it slowly cools and acquires the crystalline structure characteristic of 

 this metal ; to favour this crystallisation the metal, while cooling, is covered with 

 slag, and should be left quite undisturbed. 



It was shown by the late Dr. Matthiessen that the tendency of antimony to 

 crystallise is due to the presence of a small proportion of impurity ; antimony, in a 

 pure state, cannot be readily caused to crystallise. 



Antimony is a brittle metal, of a silvery white colour, with a tinge of blue, a 

 lamellar texture, and crystalline fracture. When heated at the blowpipe, it melts with 

 great readiness, and diffuses white vapours, possessing somewhat of a garlic smell. If 

 thrown in this melted state on a flat sheet of paper, the globule sparkles and bursts 

 into a multitude of small spheroids, which retain their incandescence for a long time, 

 and run about on the paper, leaving traces of the white oxide produced during the 

 combustion. When this oxide is fused with borax, or other vitrifying matter, it 

 imparts a yellow colour to it. Metallic antimony, treated with hot nitric acid in a 

 concentrated state, is converted into a powder, called antimonious acid, which is alto- 

 gether insoluble in the ordinary acid menstrua a property by which the chemist can 

 separate that metal from iron and copper. According to Bergmann, the specific 

 gravity of antimony is 6'86 ; but that of the purest is 6715. The alchemists had 

 conceived the most brilliant hopes of this metal ; the facility with which it is alloyed 

 with gold, since its fumes alone render this most ductile metal immediately brittle, 

 led them to assign to it a royal lineage, and distinguished it by the title of regulus, or 

 the little king. 



1 The substance of this description Is taken from some ' Notes on Antimony,' in the ' Mining and 

 Smelting Magazine,' vol. iit. p. 136. 



