3 Decomposition of the oxalate to the oxide. (Lenssen and Partridge).
4 Determination of the chlorine in cadmium chloride, by which the relation between the chloride and metallic silver was established. (Dumas.)
5 Precipitation of the bromine in cadmium bromide as silver bromide. (Huntington.)
6 The conversion of the oxalate into the sulphide. (Partridge.)
The different pieces of work will be taken up in chronological order and briefly considered.
Stromeyer, Schurigg Journ. 22, 366. 1818, determined the atomic weight of cadmium a short time after the discovery of the element. He does not describe his method in detail but established the relation between cadmium and oxygen to be:
Cd : O = 100 : 14.352.
| If the atomic weight of | oxygen = | 16, |
| ” ””” | cadmium = | 111.483. |
The very low result as compared with all subsequent work was probably due to the presence of a small amount of zinc, since the cadmium used was obtained from zinc ores and no adequate means of separation from the zinc is described.
von Hauer, Journ. f. prakt. Chem. 72, 338. 1857. His method consisted in reducing a weighed amount of cadmium sulphate to the sulphide in a stream of hydrogen sulphide, under pressure, at an elevated temperature, and weighing the sulphide. The reduction was shown to be complete by proving the absence of sulphate in the sulphide.