ANTIMONY. 191 



79.274 

 79.232 

 79-395 

 79-379 



Mean, 79.283, ± .009 



Hence, if = 16, Sb = 122.46. 



The determinations of Dumas* were pnblished in 1859. 

 This chemist sought to fix the ratio between silver and 

 antimonious chloride, and obtained results for the atomic 

 weight of antimony quite near to those of Dexter. The 

 SbClg was prepared by the action of dry chlorine upon pure 

 antimony ; it was distilled several times over antimony 

 powder, and it seemed to be perfectly pure. Known weights 

 of this preparation were added to solutions of tartaric acid 

 in water, and the silver chloride was precipitated without 

 previous removal of the antimony. Here, as Cooke has 

 since shown, is a possible source of error, for under such 

 circumstances the crystalline argento-antimonious tartrate 

 may also be thrown down and contaminate the chloride of 

 silver. But be that as it may ; Dumas' weighings, reduced 

 to a common standard, give as proportional to 100 parts of 

 silver, the quantities of SbClg which are stated in the third 

 of the subjoined columns : 



1.876 grm. SbClg = 2.660 grm. Ag. 70.526 



70.527 

 70.592 

 70.487 

 70.411 

 70.416 

 70.626 



Mean, 70.512, ± .021 



Hence, if Ag = 108, and CI = 355, Sb = 122. 



In 1861 Kessler's second paper f relative to the atomic 

 weight of antimony appeared. Kessler's methods were 

 somewhat complicated, and for full details the original 

 memoirs must be consulted. A standard solution of potas- 

 sium anhydrochromate was prepared, containing 6.1466 



*Ann. Chim. Phys., (3,) 55, 175. 

 f Poggend. Annal., 113, 145. 



