A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...

THE CHEMISTRY OF ANTIMONY. 11
The metal melts at 630*6° (ffolborn and Day). In this liquid
state it can dissolve not only the solid metal itself, but also the
sulphide of the metal.
The boiling-point of the metal under atmospheric pressure is 1300°;
it is 290° in the vacuum of cathode light (Krafft, Bergfeld). The
colour of the fume of antimony is green (Linck).
Explosive Antimony.—In a bath of hydrochloric acid and antimony
proto-chloride, with antimony metal as anode and platinum-foil as
cathode, metallic antimony is deposited upon the cathode. This
antimony is quite different from the ordinary kind. Its hardness is
less, being 5*78, and it explodes, when it is scratched with a sharp
point, with the development of heat and the setting free of white
fume. When it is rubbed with a pestle in a mortar, strong detonation
occurs, with a simultaneous development of light and heat. The same
phenomenon can be produced when the dried substance is heated to
200°, the resulting reaction product being the ordinary antimony.
Recently E. Cohen and his students have made researches into this
remarkable explosive form of antimony. It can be obtained through
electrolysis from a solution in chlorine and bromine; while, on the
other hand, from a solution in fluorine alone only the" ordinary
antimony can be obtained, without any admixture of halogens.
The important factors for the production of this particular explosive
form of antimony are a particular temperature and a particular halogen
concentration, the concentration of H being unimportant. The following
table shows the fact that the temperature to render the explosive
modification unexplosive varies directly as the concentration:—
Concentration.
10% SbCl3, at 16°-17°, shining and explosive ; 28°, not shining and not explosive.
15-6% „ at 0°, „ „ 30°,
21-2% „ at 10°, „ „ 50°,
As a rule, the higher the concentration of the electrolyte is, the
larger the quantity of the halogens taken up by the metal.
Its heat of solution is higher than that of the ordinary kind.
Hence the heat of transformation is the difference between the two,
which is calculated to be 20 to 21 calories.
The sensitiveness of the explosive modification decreases with an
increase of the amount of halogens in solution. The stability
increases as the temperature decreases. Comparatively, the explosive
modification is meta-stable. It is still uncertain "whether it is
crystalline or amorphous.
Black Antimony.—Another meta-stable form of antimony is black
antimony. It is produced when metallic antimony vapour is