REPORT OF EXECUTIVE COMMITTEE XXXI 



i. The preparation of a suitable semipermeable membrane. 



2. The overcoming of the mechanical difficulties in assembling the 

 different parts essential to the complete osmotic cell. 



3. The production of an efficient porous wall on which to deposit 

 the semipermeable membrane. 



Professor Morse has succeeded in solving the problems designated 

 by 1 and 2, and the work since October, 1902, has been prosecuted 

 by him and Mr. J.C.W. Fraser, working in the laboratory of the Johns 

 Hopkins University. They have found it necessary not only to 

 work out theoretically but also practically the problem of the pro- 

 duction of a suitable porous wall, necessitating the molding of the 

 clay under great pressure in order to give the cell wall a higher and 

 more uniform degree of compactness than is secured by the usual 

 methods of the potter, and to remove thoroughly the air blisters and 

 cavities which render most porous walls unfit for experimental work 

 in osmotic pressure. Their attention was therefore turned, in the 

 second place, to the devising of apparatus for the forming of the clay 

 vessels under pressure, with the result that they now possess two 

 pieces of apparatus which work to entire satisfaction. They next 

 proceeded to take up the problem of baking the clay vessels, and 

 devised an electric kiln which was effective and well adapted to 

 general use in the laboratory. They are now ready to begin the 

 making, baking, and burning of porous cells. 



A. A. Noyes, Massachusetts Institute of Technology, Boston, Mass. 

 Grant No. 45. For certain chemical investigations. $2,000. 



Abstract of Report. — The work under the direction of Professor 

 Noyes, on the electric conductivity of salts and aqueous solutions 

 at high temperatures, has been in progress for several months, with 

 the assistance of Dr. William D. Coolidge. Much of the time has 

 been given to the construction of an effective platinum lined con- 

 ductivity cell or bomb, suitable for exact conductivity measurements 

 with aqueous solutions up to 306 or higher, and in other prepara- 

 tory work. 



Now that the serious difficulties in the production of the con- 

 ductivity apparatus, suitable for measurements at high temperatures 

 and pressures, have been overcome, and the possibility of obtaining 

 accurate results has been demonstrated by a series of determinations 

 extending with a few salts up to 306 , it is highly desirable to ex- 

 tend the measurements to salts of other types and to acids and bases, 

 and to the critical temperature of 360 . This work is very difficult, 



