6 4 



Scientific Proceedings (117). 



advantage in the micro method lies in the possibility of greatly 

 shortening the duration of the tests, thus making it possible to 

 follow the time course of respiratory exchange over relatively short 

 periods of time. Owing to the small volumes used, temperature 

 adjustment is rapid. 



With good manipulation the maximum error is less than 0.005 

 c.c. of O2 gas. The method is being used in studies on oxygen 

 consumption by small organisms such as protozoa, eggs and certain 

 kinds of tissues. 



35 (1782) 



Does the introduction of an ethoxy group into aromatic com- 

 pounds increase their bactericidal action upon 

 the pneumococcus and the gonococcus? 1 



By ARTHUR D. HIRSCHFELDER and L. J. PANKOW. 



[From the Department of Pharmacology of the University of 

 Minnesota, Minneapolis, Minn.] 



Morgenroth and his collaborators have shown that when an 

 ethoxy group is substituted for the methoxy group in quinine 

 derivatives and ethylhydrocuprein is produced, the substance takes 

 on markedly increased pneumococcicidal action in vitro and in 

 vivo. Solis Cohen, Kolmer and Heist found that ethylhydrocu- 

 prein hydrochloride was from eight to twenty times as strong an 

 antiseptic for the pneumococcus as quinine hydrochloride. Mor- 

 genroth and Levy had shown that no such difference between 

 quinine and ethyl hydrocuprein could be observed in the case of 

 the streptococcus. We find that when cultures of gonococcus 

 are exposed to starch bouillon containing quinine hydrochloride or 

 ethylhydrocuprein in 1/10,000 dilution and then transferred to 

 plates of rabbit's blood agar, growth occurs if the exposure to the 

 drug has lasted only ten minutes but the bacteria are killed if the 

 exposure has lasted thirty minutes. Ethylhydrocuprein has 

 therefore no specific action against the gonococcus. However, 

 as ethylhydrocuprein is too toxic for successful use in the chem- 



1 The investigations recorded in this paper were rendered possible by a grant of 

 funds granted by the United States Interdepartmental Social Hygiene Board, for 

 the discovery of better medical measures for the prevention and treatment of the 



venereal diseases. 



