Physiological Efficiency of Acids 



135 



butyric acid, the other with benzoic. As usual, the acid was 

 diluted with half grammolecular sodium chloride solution. 



TABLE XIX 



Length of 

 Exposure to- 



BuTYBic Acid 



3/5,000 



N 



5/5,000 



N 



6/5,000 



N 



7/5,000 



N 



8/5,000 



N 



10/5,000 



N 



5 minute . 



1 minute. . 

 li minutes 



2 minutes . 

 2j minutes 



3 minutes . 



4 minutes . 



5 minutes . 



6 minutes . 



7 minutes . 















2% 



3 



5 

 30 

 40 

 80 

 90 





 



48% 



60 



95 







14% 

 95 

 100 



5% 

 100 



5% 

 100 



5% 

 100 



TABLE XX 



As a rule membrane formation cannot be elicited by the 

 use of butyric acid at a lower concentration than 3/5,000 N. 

 Even at concentrations of 3/5,000 N butyric acid is usually 

 without effect. When, however, the effective value is attained, 

 the optimum concentration is also quickly reached. The same 

 is true of benzoic acid, only in this case the effective value is 

 much lower than for butyric acid, being 18/50,000' N. 



