A great deal of time was spent in trying to effect a partial synthesis of cadmium bromide in exactly the same manner as had been used in case of cadmium sulphate. No results were obtained because cadmium bromide is slowly volatile at 150°C, the temperature used, and retained some hydrobromic acid ever after more than 100 hours of drying. Some work was done in trying to establish the ratio between silver and Cadmium by dropping a weighed piece of cadmium into a solution of silver sulphate, the reaction being: Cd + Ag_{2}SO_{4} = CdSO_{4} + 2Ag Silver nitrate cannot be used because it becomes reduced to nitrate even at a temperature of 0°C., as was shown by its reducing action on potassium permanganate, and by the reaction with meta-diamido benzene after the reaction had been completed. The main difficulty with the method is that air must be excluded in order to prevent oxidation and solution of some of the precipitated silver. The silver is perfectly free from cadmium if an excess of silver sulphate is used and the precipitated metal digested with it for some time. Since this part of the work was done, a paper by Mylius and Fromm (Ber. 1894, 630) appeared in which one of the reactions studied was that of cadmium on silver sulphate. They also found the resulting silver free from cadmium. The method seems very promising, but the work had to be discontinued for lack of time. Conclusion. I. The work on the oxalate and sulphide methods described in this paper is of no value for determining the atomic weight of cadmium. It does not even enable us to fix an approximate value. II. There are a number of errors in the chloride and bromide methods as they were used in this work, but they are not very large and partially compensate each other. Their results, 112.383 and 112.396 respectively, may be regarded as approximations to the true value. III. The synthesis of cadmium sulphate as carried out is of especial value in fixing a _minimum_ value for the atomic weight of cadmium. The result is 112.35, agreeing closely with that obtained by the bromide and chloride methods. IV. There is an error in the oxide method due to products of decomposition of the nitrate being retained. Direct experiments gave .39 of a unit for this when platinum crucibles were used and .24 of a unit when porcelain ones were used. The calculated errors for porcelain and platinum crucibles are .30 and .51 of a unit respectively, if 112.38 is assumed as the atomic weight of Cadmium. V. The average of the chloride, bromide, and sulphate methods is 112.38. This result is to be regarded as _tentative_ and not as final since the main object of this work has been to find the cause of the discrepancy in some methods employed in determining this constant, rather than to make an atomic weight determination. Biographical Sketch.