154 REPORTS ON INVESTIGATIONS AND PROJECTS. 



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

 chusetts. Grant No. 239. Researches upon (/) Electrical conduc- 

 tivity of salts in aqueous solution at high temperatures; (2) Ionization 

 of zveak acids and bases and hydrolysis of their salts in aqueous solu- 

 tion at high temperatures ; (j) Trajisference determinations in 

 aqueous solutions. (For previous reports see Year Book No. 2, 

 p. xxxi, and Year Book No. 3, p. 109.) $2,000. 



These three researches have been continued during the past year 

 in the Research Laboratory of Physical Chemistry of the Massachu- 

 setts Institute of Technology. The first has been executed with the 

 assistance of Dr. William D. Coolidge and Mr. Arthur C. Melcher ; 

 the second with that of Mr. Yogoro Kato and Mr. Robert B. Sosman, 

 and the third with that of Mr. Edward W. Washburn and Mr. Ralph 

 S. Gifford. The work upon all these investigations has progressed 

 •so far that a series of ten articles describing fully the methods and 

 results will soon be submitted to the Carnegie Institution of Wash- 

 ington for publication. 



Since the report was made a year ago the work done upon the first 

 investigation, on the electrical conductivity of aqueous solutions at 

 high temperatures, has consisted in the extension of the measure- 

 ments previously made with silver nitrate, potassium sulphate, and 

 barium nitrate at temperatures up to 21 8° to the still higher tem- 

 peratures 28 1 ° and 306 . By the results of these measurements the 

 conclusions stated in the previous report in regard to the effect of tem- 

 perature on the ionization of substances and the migration velocities 

 of ions have been more fully confirmed. It has been found espe- 

 cially that the decrease of ionization becomes extremely rapid at the 

 highest temperature interval investigated — that is, between 281 ° and 

 306 . In order to extend the measurements up to and through the 

 critical temperature, a radical modification of the conductivity appa- 

 ratus is necessary, since thorough agitation, measurements at a series 

 of small temperature-intervals, control of the pressure upon the solu- 

 tion, and resistance of the apparatus to a much higher pressure must 

 be provided for. Much progress has already been made in adapting 

 the apparatus to these conditions, and it is hoped that it will be 

 entirely perfected during the coming year. 



The second research on the ionization of weak acids and bases 

 and the hydrolysis of their salts has been continued by measuring 

 the conductivity of ammonium hydroxide and acetic acid at a series of 

 temperatures up to 218 , and studying the hydrolysis of ammonium 

 acetate at ioo°,i56°, and 2 1 8° by the method described in the preced- 



