(36 ANTIMONY. 



circumstances as arsenic, (L. Thompson.) Antimony, however, 

 may be recognized by a peculiarity of its reduction in the ignited 

 tube. This metal is deposited in the tube, on both sides of the 

 heated portion of it, and closer to the flame than arsenic, owing 

 to the less volatility of antimony. The white sublimate also, 

 if dissolved in water containing a drop of ammonia, will not 

 give the proper indications with the fluid tests of arsenic, if the 

 metal is antimony. 



Antidote to arsenious add. When hydrated peroxide of iron 

 is mixed with a solution of arsenious acid to the consistence of 

 a thin paste, a reaction occurs by which the arsenious acid dis- 

 appears in a few minutes, and the mass ceases to be poisonous. 

 The arsenious acid derives oxygen from the peroxide of iron, 

 and becomes arsenic acid, while the peroxide of iron becomes 

 protoxide, a protarseniate of iron being the result, which is in- 

 soluble and inert : 



2Fe 2 O 3 and AsO 3 = 4FeO+AsO 5 . 



The constitution of this arseniate of iron is probably 2FeO. HO, 

 AsO 5 + 2FeO. Peroxide of iron, when used as an antidote to 

 arsenious acid, should be in a gelatinous state as it is obtained 

 by precipitation, without drying. It may be prepared extem- 

 poraneously, by adding bicarbonate of soda in excess to any 

 tincture, or red solution of iron. 



SECTION II. 

 ANTIMONY. 



Eq. 1612.9 or 129.24 ; (806.4 or 64.62 Berzelius and Turner} ; 

 Sb (stibium). 



This metal was well known to the alchemists, and is one of 

 the metals of which the preparations were first introduced 

 into medicine. Its sulphuret is not an uncommon mineral, 

 and is the source from which the metal and its compounds are 

 always derived. 



The sulphuret of antimony is easily reduced to the metallic 

 state by mixing together 4 parts of that substance, 3 parts of 

 crude tartar and l parts of nitre, and projecting the mixture by 

 small quantities at a time into a red hot crucible. The sulphu- 

 ret is also sometimes reduced by fusion with small iron nails, 



