148 REPORTS ON inve;stigations and proje^cts. 



average from both series being 54.96, referred to silver 107.930. The com- 

 plete account of this investigation will soon be published in the Journal of 

 the American Chemical Society for November, 1906, and also in the Zeit- 

 schrift fiir anorganische Chemie. 



(2) An investigation upon the atomic weight of cadmium, begun some 

 years ago by Dr. Hines by analysis of cadmium chloride (see Journal of the 

 American Chemical Society, 27, 222 (1905), and Zeitschrift fiir anorgan- 

 ische Chemie, 44, 158, was continued by Dr. Hines and Mr. Harry Iv. 

 Frevert by the analysis of cadmium bromide. Here also weighed portions 

 of the fused salt were first titrated against pure silver, and then the precipi- 

 tated silver bromide was collected and weighed. Since in the investigation 

 upon manganous chloride it was found that phosphorus pentoxide is slightly 

 attacked by hydrochloric acid gas, new analyses of cadmium chloride were 

 completed, in which the salt was fused in a current of hydrochloric acid 

 which had been dried by concentrated sulphuric acid only. These analyses, 

 however, agreed very closely with the analyses of cadmium bromide, and 

 also with the previous analyses of cadmium chloride, although in the earlier 

 work phosphorus pentoxide had been used as a drying agent for the hydro- 

 chloric acid gas. The atomic weight of cadmium, referred to silver 107.930, 

 was found to be 112.47. The results of this research have already been 

 published in the Journal of the American Chemical Society, 28, 770 (1906), 

 and in the Zeitschrift fiir anorganische Chemie, 49, 415. 



(3) The atomic weight of bromine was determined by Professor Baxter 

 both by synthesis of silver bromide from weighed amounts of silver and by 

 the conversion of silver bromide into silver chloride. If the atomic weight 

 of silver is 107.930, the atomic weight of bromine is found to be 79.953. 

 This investigation has already been described in full in the proceedings of 

 the American Academy of Arts and Sciences, 42, 201 (1906), the Journal of 

 the American Chemical Society, 28, 1322, and the Zeitschrift fiir anorgan- 

 ische Chemie, 50, 389. 



(4) Dr. Hines also commenced an investigation upon the atomic weight 

 of chromium. Silver chromate was precipitated by addition of a dilute 

 silver nitrate solution to a dilute solution of ammonium chromate. After 

 being dried at 200° the salt was dissolved in nitric acid and the silver was 

 precipitated by either hydrochloric or hydrobromic acid. Then the pre- 

 cipitated silver halide was collected and weighed. Difficulty was experi- 

 enced in preparing silver chromate free from dichroraate. Furthermore, 

 it was found impossible to eliminate all moisture from the silver chromate; 

 hence a correction for this moisture was determined. This research is not 

 yet completed. The reduction of silver chromate in hydrogen is also under 

 investigation. 



(5) With Mr. George S. Tilley an attempt to refer the atomic weight 

 of iodine directly to that of oxj^gen has been made through the analysis 



