356 CARNEGIE INSTITUTION OF WASHINGTON. 



The work of Dr. Wightman and Mr. Wiesel on the conductivity of 

 organic acids in ethyl alcohol has been greatly extended during the past 

 year by Dr. Lloyd and Mr. Wiesel. Nearly 40 organic acids have been 

 studied by these investigators in this solvent. The conductivity of 

 organic acids in general in ethyl alcohol is surprisingly small when we 

 consider the relative dissociating powers of water and ethyl alcohol in 

 their action on salts. The temperature coefficients of conductivity of 

 the organic acids in this solvent are large. 



Dr. Watkins has extended the work on the conductivity and dis- 

 sociation of salts in water, as measured by their conductivity, which 

 has been in progress for the past 15 years, and the results of which 

 have appeared in PubUcation 170 of the Carnegie Institution of Wash- 

 ington. He has worked with a number of rather unusual salts with 

 very great care, over a wide range of dilution, and at several temper- 

 atures. The results obtained in general confirm the conclusions drawn 

 from earher work on this same general subject. 



Mr. Ordemann has investigated the relative dissociating powers of 

 free and of combined water, in the following manner. He prepared 

 isochloric solutions of potassium chloride and calcium chloride, the 

 one only a sHghtly hydrated and the other a strongly hydrated com- 

 pound. These solutions were used as a solvent: in one, nearly all of 

 the water existing as free water; in the other much of the water being 

 combined with the calcium chloride as water of hydration. 



Certain salts were dissolved in these two solvents, and the dissocia- 

 tions of the salts in question were measured by means of the conduc- 

 tivity method. The two solutions were made isochloric, in order to 

 drive back the dissociation of the dissolved salts to the same extent. 

 While the results thus far obtained are too few in number to justify 

 the drawing of any final conclusion, it seems highly probable, from what 

 has already been done, that combined water or water of hydration has 

 less power to break down dissolved molecules into their ions than free 

 or uncombined water. 



The problem of absorption or adsorption of certain substances by 

 soils has been studied by Mr. McCall, with the cooperation of Messrs. 

 Hildebrandt, Johnston, F. G. Holmes, and Trelease. They found that 

 the potassium from solutions of potassium chloride is partly combined 

 chemically with or absorbed by the soil particles, and partly adsorbed 

 or held physically by the soil particles; the fineness of the division of the 

 soil having a marked effect on the amount of the potassium salt ab- 

 sorbed or combined chemically, and also that adsorbed or in a condition 

 of physical combination. It appears that, under certain conditions, the 

 solvent water may be adsorbed even more rapidly than the salts. 



The results of these investigations are recorded in Pubhcation 230 

 of the Carnegie Institution of Washington, pubUshed in October 1915. 



