ABSTRACTS 



Authors ot scientific papers are requested to see that abstracts, preferably 

 prepared and signed by themselves, are forwarded promptly to the editors. 

 The abstracts should conform in length and general style to those appearing in 

 this issue. 



PHYSICAL CUUMISTRY .—Application of the thermionic amplifier 

 to conductivity measurements. R. E. Hall and L. H. Adams. 

 Joum. Amer. Chem. Soc. 41: 1515-1525. Oct., 1919. 



As a part of the general plan for the investigation of two com- 

 ponent systems under pressure, a study is being made of the changes 

 in solubility of a salt which occur when its aqueous solution, in contact 

 with crystals of the solid, is subjected to pressure. In order to measure 

 the changes of concentration which occur in the solution, while leav- 

 ing it in situ in the pressure bomb, we note the changes in the conduc- 

 tance of the solution. For the attainment of sufficient accuracy in 

 these measurements, the telephone which indicates the balance posi- 

 tion of the Wheatstone bridge must be extremely sensitive since the 

 allowable current through the network is limited by heating effects in 

 the conductivity cell. The terminals of the bridge which ordinarily 

 are connected to the telephone are joined to the "input" of a thermionic 

 amplifier, of the type used in wireless telephony and telegraphy. The 

 telephone is then connected into the output circuit of the amplifier. 

 This arrangement has resulted in effectively increasing by approxi- 

 mately 50 times the sensitivity of a sensitive high-resistance tele- 

 phone. Any ordinary telephone becomes a more sensitive instrument 

 with the amplifier than the best telephones withotit it. R. E. H. 



PHYSICAL CWEMISTRY .—Eqtiilibrium studies upon the Bucher 

 process. J. B. Ferguson and P. D. V. Manning. Joum. Ind. 

 Eng. Chem. 11: 946-950. Oct., 1919. 



An investigation of the Bucher or cyanide process for the "fixation" 

 of atmospheric nitrogen was undertaken at the suggestion of the War 

 Department. Experiments wer.e made using pure chemicals and mix- 

 tures of pure nitrogen and carbon monoxide in known proportions. 

 Curves were obtained showing (i) the relation between the carbon 

 monoxide content of the furnace gases and the yield of cyanide, and (2) 



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