156 REPORTS ON INVESTIGATIONS AND PROJECTS. 



corrected for all discoverable sources of error, are Na = 23.006 and 

 CI = 35-47o. if Ag = 107.920. 



(2) A continuation of the study of the compressibility of elements 

 and simple compounds carried on with the assistance of Dr. Wilfred 

 Newsome Stull. The earlier results of Richards and Bonnet were 

 confirmed and the compressibilities of a majority of the chemical 

 elements were determined. Besides affording interesting evidence 

 concerning the significance of atomic volume, these results add weight 

 to the Mendeleev-Meyer classification of the elements, showing well- 

 marked periodicity. In addition to these data, many compressibili- 

 ties of simple compounds were determined, all of which agree with 

 the predictions of the recent theory of compressible atoms. The 

 method of Richards and Stull (Carnegie Institution Publication No. 7) 

 continued to give satisfaction. The experimental work has reached 

 a stage demanding further publication and is now being codified and 

 described for this purpose. 



(3) An investigation of the effect of pressure and strain upon the 

 electromotive force of pure iron immersed in solutions of its salts, 

 carried on with the assistance of Gustavus E. Behr, jr. This investi- 

 gation afforded conclusive evidence concerning the effects of pressure, 

 temperature, and the occlusion of hydrogen upon the electromotive 

 force, and therefore upon the tendency of iron to rust. The work 

 of C. Hambuechen was conclusively disproved. The results have a 

 practical bearing as well as considerable theoretical interest, and will 

 be described for publication as soon as possible. 



(4) A research upon the electromotive force of cells composed of 

 amalgams of different strengths, carried on with the assistance of 

 Dr. George Shannon Forbes. This investigation needs only a few 

 more weeks of experimental work for its completion, and is already 

 in part in form for publication. The plan is comprehensive, includ- 

 ing (a) the determination of the deviations of the electromotive 

 forces from those demanded by the gas law, (J?) the heat of dilution 

 of the amalgams, (c) the heat capacities of the amalgams. Both 

 zinc and cadmium amalgams were studied, and results of great con- 

 sistency and precision were obtained. The interest of this work lies 

 mainly in its relation to the theory of thermodynamics ; the details 

 are too complex for brief presentation. As soon as possible this 

 work also will be published. 



(5) The determination of the specific heats of certain systems 

 over wide ranges of temperature, carried on with the assistance of 

 Gustavus E. Behr, jr. , and Richard Fay Jackson. This work is in its 



