CHEMISTRY. 281 



The study of the conductivities and viscosities of solutions of 

 electrolytes in pure and mixed solvents was extended to acetone as a 

 solvent, and to mixtures of acetone and water, by Dr. Davis and Dr. 

 Hughes. The salts investigated were the chloride, bromide, iodide, 

 and nitrate of rubidium. These salts were chosen because of the 

 large atomic volume of rubidium; and acetone was selected as the 

 solvent because it so frequently manifests abnormal behavior and 

 gives abnormal results. Acetone was chosen for viscosity work 

 because it has comparatively small viscosity— glycerol, with very 

 large viscosity, having already been studied for some years past. 

 These salts could not be studied in pure acetone on account of their 

 comparative insolubility. They were, however, investigated in mix- 

 tures of acetone and water. The salts of rubidium were found to 

 increase the viscosity except in those mixtures containing the largest 

 per cent of water. The iodide and nitrate of rubidium, which pro- 

 duced the greatest lowering of the viscosity of mixtures of glycerol 

 and water, actually raised the viscosity of mixtures of acetone and 

 water until a 5 per cent acetone mixture was reached. These 

 same salts showed a diminution in viscosity in mixtures containing 

 only a little acetone. They seem to have no effect on the viscosity 

 of a mixture of 50 per cent acetone and 50 per cent water. When 

 there is more than 50 per cent acetone present, they increase the 

 viscosity of the mixed solvent in which they are dissolved. Rubidium 

 salts give minima in the conductivity curves in a higher percentage 

 of acetone than the minima in the fluidity curves. For some salts 

 those two curves run parallel. The temperature coefficients of con- 

 ductivity and of fluidity are about what would be expected. 



The work on the conductivity, dissociation, and constants of the 

 organic acids in water was extended during the year by Dr. L. D. 

 Smith. He worked with a fairly large number of somewhat un- 

 common acids, at various dilutions and temperatures. Relations 

 of interest, and it is hoped of some value, were established. 



Morse, H. N., Johns Hopkins University, Baltimore, Marj'land. Grant No. 

 830, allotted Dec. 13, 1912, Measurement of the osmotic pressure of 

 solutions. (For previous reports see Year Books Nos. 2-11). $4,000 



It has been shown in earlier reports with respect to all solutions of 

 cane-sugar ranging in concentration from 0.1 to 1.0 weight-normal: 



(1) That the ratio of the observed osmotic pressure to the calcu- 

 lated gas-pressure of the solute is constant for each concentration 

 between 0° and 25°, which indicates that the law of Gay-Lussac for 

 gases holds between these temperatures. 



(2) That between 0° and 25° the osmotic pressures are not propor- 

 tional to the supposed concentration of the solutions, which leaves 

 the applicability of the law of Boyle in doubt. 



