200 REPORTS OP INVESTIGATIONS AND PROJECTS. 



been developed to its present state, and a repetition of that work under the 

 improved conditions may alter somewhat the ratio in question. On the 

 other hand, it may be found that osmotic pressure, like the volume of the 

 solvent, diminishes through a certain temperature interval above o°. The 

 measurements at o° and at 5° will be repeated, and other series of determina- 

 tions at 20°, 25°, and 30° will be carried out. That at 25°, as stated above, 

 is already nearly finished, and the results lead to the same conclusion as do 

 those at 10° and 15°. 



An account of the work upon cane-sugar solutions at 10° and 15° will be 

 found in the numbers of the American Chemical Journal for June and 

 August, 1908. 



Drs. B. F. Lovelace and W. W. Holland have cooperated with the author 

 of this report in the work of the past year. He has also had, throughout 

 that time, the valuable assistance of Messrs. B. Mears and H. V. Morse. 



Noyes, Arthur A., Massachusetts Institute of Technology, Boston, Massa- 

 chusetts. Grant No. 501. Researches upon (i) Electrical conductivity 

 of aqueous solutions at high temperatures ; (2) Electrical transference 

 determinations in aqueous solutions. (For previous reports see Year 

 Books Nos. 2, 3, 4, 5, and 6.) $3>ooo- 



These researches have been continued during the past year in the Research 

 Laboratory of Physical Chemistry of the Massachusetts Institute of Tech- 

 nology. The first has been executed with the assistance of Mr. Arthur C. 

 Melcher, Mr. Roy D. Mailey, and Dr. John Johnston, and the second with 

 that of Dr. Edward W. Washburn. 



During the past year the following lines of work have been pursued : 



(i) The conductivity and ionization of salts of the higher valence types in 

 aqueous solution at temperatures between 0° and 156° have been deter- 

 mined; six salts (calcium nitrate, potassium oxalate, calcium and barium fer- 

 rocyanides, and lanthanum nitrate and sulphate) have been investigated in 

 this way at a number of different concentrations. The results show that the 

 higher the product of the valences of the constituent ions the smaller the ion- 

 ization at a given temperature and concentration ; that for all types the change 

 of ionization with the concentration follows the same empirical exponential 

 law (contrary to the requirements of the mass-action principle) ; and that in 

 all cases the ionization decreases steadily with the temperature. This line of 

 work is to be continued during the coming year. 



(2) The solubilities in water of a few important difiicultly soluble salts 

 (calcium sulphate, barium sulphate, and silver chloride) have been deter- 

 mined up to 100° or 156° by measuring the electrical conductivity of their 

 saturated solutions. 



