12 PROCEEDINGS OF THE AMERICAN ACADEMY 



Specimen A was prepared from potassic antimoniate (marked Ro- 

 biquet and Pelletier, pur). A solution of the salt in water was filtered 

 into a similar hot solution of sodic carhonate. The precipitated sodic 

 antimoniate was thoroughly washed with hot water, then dried, and 

 reduced with potassic cyanide. Lastly, the regulus was reraelted, and 

 kept in fusion for several hours under its own oxide. Specimen B 

 was prepared, in a similar way, from potassic antimoniate (marked 

 Rousseau Freres, pur). Specimen C was prepared from commercial 

 antimony. The metal was first oxidized, and the oxide boiled with an 

 excess of pure nitric acid. Tlie oxide was afterwards repeatedly washed 

 with boiling water, and, when dried, was reduced with potassic cyanide. 

 A third of the resulting metal was again oxidized with nitric acid ; and 

 this oxide having been first mixed with the rest of the metal, previously 

 pulverized, the mixture was kept melted for a long time in a covered 

 crucible. The purified metal thus obtained was again fused in a porce- 

 lain crucible, under its own oxide, for several hours. Specimen D was 

 the residue of C, — part having been used for casting bullets, — again 

 fused for several hours under its own oxide. Specimen E was prepared 

 by the process described above from potassic antimoniate, made by our- 

 selves from commercial antimony. It was fused for four hours under 

 its own oxide. Specimen F was prepared by Liebig's well-known 

 process, and further purified by fusing the regulus for twenty-nine hours 

 under its own oxide. It is unnecessary to add that these fusions were 

 all made in [lorcelain crucil)les, and that only the purest reagents were 

 employed in the various processes, except only in the early stages of the 

 preparation of C and F. These last preparations were both used 

 for casting the antimony bullets with which the solutions of the 

 metal were reduced before precipitating with II^S, as will be described 

 hereafter. 



We give, in a parallel column with our own results, the specific 

 gravities, determined by Mr. Dexter, of the specimens of pure anti- 

 mony prepared by him, and used in his determinations of the atomic 

 weight of this element. It will be noticed tliat the agreement is very 

 close, the mean of his results not differing from that of ours as much 

 by one-half as either set differ amom^ themselves. Tliese ditterences 

 are evidently owing to slight variations in homogeneity, due to tlie 

 crystalline structure of the metal. This is made probable by the fol- 

 lowing results which we obtained with specimen F, prepared as 

 described above by Liebig's process. This was repeatedly fused in 

 its own oxide, and the specific gravity taken at each stage of the 

 process. 



