A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
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THE ANTIMONY PREPARATIONS AND THEIR USES. 159<br />
should the gas be accompanied by a large proportion of steam. The<br />
chloride of antimony thus obtained is diluted with water to 25° Be.<br />
" The two solutions of antimony and of hyposulphite being prepared,<br />
we proceed as follows:—We pour into a stoneware vessel 4 litres<br />
of chloride of antimony, 6 litres of water, and 10 litres of hyposulphite<br />
of soda. The precipitate caused by the water is rapidly<br />
dissolved in the cold by the hyposulphite. The vessel is then placed<br />
in a hot-water bath, where the temperature of the mixture is<br />
gradually raised. At about 30° C. the precipitate of sulphite begins<br />
to form; it is orange-yellow at first, and becomes darker afterwards.<br />
At 55° C. the vessel is removed from the water-bath and the precipitate<br />
is allowed to settle, which it does rapidly. The motherliquors<br />
are decanted, and the deposit is washed, first with water<br />
holding -j^- of HC1, and afterwards with ordinary water. Lastly, the<br />
precipitate is collected upon a filter and dried. The wet vermilion<br />
of antimony is of an exceedingly bright red colour; after drying, it<br />
loses part of its brightness. This pigment may be prepared in the<br />
cold, but the product is finer and more constant if we operate in the<br />
manner just described.<br />
" Being certain to reproduce my new sulphide whenever it is<br />
desired, I have undertaken its analysis. But as the determination<br />
of the antimony is very difficult, and as there is no known method<br />
sufficiently accurate for the purpose, I have determined the sulphur<br />
and calculated the antimony by difference. It has also been necessary<br />
to determine the proportion of water. Moreover, I have compared<br />
the oiange-yellow sulphide with my own, and the result is:—<br />
0*668 of orange-yellow sulphide loses 0 # 038 at 200° C.<br />
0*808 of red sulphide loses 0*009 at 200° C.<br />
"This proves that the vermilion of antimony is an anhydrous substance,<br />
and that the above shown is due to imperfect drying.<br />
" There now remains to prove by analysis that the vermilion of<br />
antimony differs from the orange-yellow sulphide by only one<br />
equivalent of water. This explains the new properties of the red<br />
sulphide. I have found by analysis:—<br />
Water 1*1<br />
Sulphur 26*7<br />
Antimony (by difference) . . .72-2<br />
100-0<br />
which composition proves that the equivalents of sulphur and antimony<br />
are in the ratio 3:1."