CHEMISTRY. 385 



weight, but the investigation was interrupted by ill health. He ex- 

 pects to continue it in the autumn. 



(4) The Thermodynamic Behavior of Sodium Amalgams. 



Mr. John Russell, 1851 Exhibition Scholar from McGill University, 

 continued his investigation of sodium amalgams. He redetermined 

 with greater care the heat-capacity changes on dilution and the data 

 have been correlated and show thermodynamic consistency. Serious 

 errors in the previous work of others have been discovered. 



(5) Heat of Reaction of Slow Chemical Reactions. 



Mr. Oscar C. Bridgeman has continued the study of this problem. 

 His very complicated apparatus was perfected so that during many 

 hours the environment of a calorimeter changing in temperature 

 could be kept automatically to within 0.001° the same as that of the 

 calorimeter itself. This is perhaps the most perfect adiabatic calori- 

 meter ever constructed. IVIost of the year was consumed in the per- 

 fection of the apparatus, but during the last month the catalytic de- 

 composition of methyl acetate was studied in a preliminary way. 

 The reaction was found to be markedly endothermic, and the only 

 further requirement for the procuring of final results on this and many 

 other similar reactions is the preparation of chemically pure sub- 

 stances, which is already under way. Incidentally, while the appa- 

 ratus was being perfected, the purification of methyl acetate was 

 critically studied and several previously unsuspected causes of impu- 

 rity have been detected, and (so far as can be seen) eliminated. 



(6) Compressibilities of Simple Salts. 



Mr. Edouard P. R. Saerens, Belgian Research Fellow, began the 

 study of the compressibility of various simple salts, continuing the 

 research carried out by Dr. Grinnell Jones in 1908. (See Carnegie 

 Year Book No. 7, 1908; Journal of the American Chemical Society, 

 vol. 31, page 158, 1909.) He undertook especially the study of the 

 compressibility of the halides of the rarer alkali metals, beginning 

 with csesium chloride. The results are expected to be of especial 

 interest in relation to the recent computations of Born concerning 

 the nature of the distance-effect by chemical affinity, as well as in 

 relation to atomic compressibility in general. 



(7) Electrode Potentials and Junction Potentials. 



With the help of Mr. Theodore Dunham jr., an investigation was 

 conducted concerning the effect of varying hydrogen-ion concentration 

 on the electrode potential of metals. This investigation was prompted 

 by the peculiar behavior of gallium, discovered in the course of the 

 previous research upon that metal and communicated in the last re- 

 port. He found that the junction potentials of the several solutions 

 gave a much larger effect than that of the acid upon the metallic 

 electrode itself, and therefore undertook a systematic study of junc- 



