1915] 



MERRILL ELECTROLYTIC DETERMINATION OF EXOSMOSIS 



549 



previous figu 



The 



substances, however, even in the 



small concentration employed, produced a marked rise in the 

 conductivity of the medium during the first day, after which 

 it remained practically constant. The benzaldehyde and the 



TABLE VII 



CONDITION OF PLANTS EIGHT DAYS SUBSEQUENT TO TREATMENT WITH 

 EFFECTIVE CONCENTRATIONS OF ANESTHETICS FOR A SHORT PPnmn 



Culture no. 



19 

 20 



21 

 22 



23 

 24 

 25 

 26 



27 



Condition of tops 



Normal and in good condition 



Practically normal 



Somewhat subnormal 



Some stems considerably affected, others 



almost normal 



Practically all dead 



About the same as in No. 22 



Considerably subnormal 



Normal; many green, vigorous, turgid 

 leaves 



Practically normal 



Condition of roots 



Considerably flaccid 

 More flaccid than those 



of No. 19 

 Somewhat flaccid 



Considerably flaccid 

 Very flaccid 



Considerably flaccid 

 Very flaccid 



Practically normal 

 Normal 



ethyl acetate, which themselves 



giv 



high conductivity 



should be considered apart from the other 



substances, which give no such 



The two substances 



mentioned are given here merely for the purpose of compari- 

 son with the others employed. A 1 per cent solution of ethyl 

 acetate had a conductivity of 65.2 on the Wheatstone bridge, 

 while that of a similar solution of benzaldehyde was 88.6. 

 These corrections should therefore be applied to the curve 

 values in order to obtain the true value of the exosmosis from 



the roots in those cultu 

 8 days is given in table 



condition of the plants after 



VIII. Effects of Substances Used Singly and Combined in 



Pairs 



It is not the writer's purpose here to go into the historical 

 aspect of the increasingly voluminous work on toxic agents, 

 antagonistic action, and balanced solutions, and the numerous 

 related subjects. But since those subjects have assumed such 

 great importance in the realm of physiology it was thought de- 

 sirable to consider the effect of certain toxic and unbalanced 



