OF ARTS AND SCIENCES. IS 



Specific Gravity of Specimen F. 

 After five hours' fusion, additional . . . 6.7050 



6.6977 

 6.6959 

 6.6840 



„ nine „ „ „ ... 6.7022 



„ several „ „ „ ... 6.7012 



Such irregular variations as these could obviously not be referred 

 to a gradual change in the purity or composition of the metal. 



Of the several processes employed for purifying antimony, the last is 

 the easiest, yields the largest product, and is as effectual as either of the 

 other two. The long fusion of the metal under its own oxide can in 

 no case be avoided, as this is the only sure method of removing the last 

 traces of iron, at least so far as our experience extends. In repeating 

 the work, however, we should prefer to start from antimonious chloride, 

 prepared fi'om antimony glance. This can easily be purified by re- 

 peated distillation, and is absolutely free from arsenic, which cannot 

 always be said of the metal obtained by Liebig's process. 



To bring a given quantity of antimony into solution, so that the 

 whole shall be left in its condition of lowest quantivalence, and there- 

 fore be precipitated by H^S as antimonious sulphide, without the least 

 excess of sulphur, we found to be a very difficult task ; nor have we 

 succeeded invariably in effecting tliis result, except by the indirect 

 method hereafter described. Finely powdered antimony dissolves 

 readily when digested with a concentrated solution of tartaric acid, to 

 which a few drops of nitric acid have been added ; but from such a solu- 

 tion, even after the remaining nitric acid has been carefully neutral- 

 ized, free sulphur is always precipitated with the sulphide of antimony ; 

 and, although we tried various ways, we were unable to find any pro- 

 cess by which this effect could be wholly prevented. Very singularly 

 we obtained the best results by acting on antimony directly with 

 nitric acid, under such regulated conditions that the metal was wholly 

 converted into antimonious nitrate, and subsequently removing the ex- 

 cess of acid by slow evaporation at a temperature below 100° C. If 

 the conversion is successfully accomplished, then, on adding to the 

 crystalline residue a strong solution of tartaric acid, this residue is at 

 once dissolved, giving a perfectly clear solution, in which the metal is 

 almost wholly, if not entirely, in its lower condition of quantivalence. 

 The ditficulty consists in regulating the action of the nitric acid. We 

 succeeded best by using acid of the sp. gr. 1 .35, which we added in large 



