31-4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 54 



AXTT:\rOXY. 



After some earlier, unsatisfactory deterniinations, Berzeliiis/ in 1826, 

 published his final estimation of tlie atomic wei,;zht of antimony. He 

 oxidized the metal by means of nitric acid, and found that 100 parts of 

 antimony gave 124.8 of Sb,0,. Hence Sb = 129.03. The value 129 

 remained in general acceptance until 1855, when Kessler,^ by special 

 volumetric methods, showed that it was certainly much too high. Kess- 

 ler's results will be considered more fully further along, in connection 

 witli a later paper; for present purposes a brief statement of liis earlier 

 conclusions will suffice. Antimony and various compounds of antimony 

 were oxidized partly by potassium dichromate and partly by potassium 

 chlorate, and from the amounts of oxidizing agent required tlic atomic 

 weight in question was deduced : 



By oxidation of Sb.O, from 100 parts of Sb Sb = 123.84 



By oxidation of Sb with K,Cr,0, " = 123.61 



By oxidation of Sb with KCIO., + K,Cr,A " = 123.72 



By oxidation of S1),0, with KCIO, + K,Cr,0; " = 123.80 



By oxidation of Sb-,S, with K,CrA " = 123.58 



By oxidation of tartar emetic " ^ 119.80 



The figures given are those calculated by Kessler himself. A recalcu- 

 lation with our newer atomic weights for 0, K, CI, Cr, S and C would 

 yield slightly different values. It will be seen that five of the estimates 

 agree closely, while one diverges widely from the others. It will be 

 shown hereafter that the concordant values are all vitiated by constant 

 errors, and that the exceptional figure is also worthless. 



Shortly after the appearance of Kessler's first paper, Schneider^ pub- 

 lished some results obtained by the reduction of antimony sulpliide in 

 hydrogen. The material chosen was a very pure stibnite from Arnsberg, 

 of which the gangiie was only qmirtz. This was corrected for, and cor- 

 rections were also applied for traces of undecomposed sulphide carried 

 off mechanically by the gas stream, and for traces of sulphur retained 

 by the reduced antimony. The latter sulphur was estimated as barium 

 sulphate. From 3.2 to 10.6 grammes of material were taken in each ex- 

 periment. The final corrected percentages of S in Sli^S., were as follows: 



' Poggend. .\nnalen, 8, 1. 



- Poggend. Annalen, 95, 215. 



■■' Poggend. .\nnalen, 98, 293. 1856. Preliminary note in Bd. 97. 



