1915] 



MERRILL ELECTROLYTIC DETERMINATION OF EXOSMOSIS 



545 



80 



75 



70 



65 



& 



60 



L 



12 



p 



2 



HI 



55 



50 





45 



c 



40 



35 



IS 



30 



25 



20 -j 



15 



10 



5 



1 



2 



3 



4 



5 



6 



7 



8 



9 



Days 



Fig. 12. Conductivity curves of cultures (series 15) in distilled water 

 subsequent to treatment, as follows: No. 3, ether vapor, 30 minutes, roots 

 exposed; No. 4, 4 per cent ether in water, 30 minutes; No. 5, illuminating 

 gas, 15 minutes, roots exposed; No. 6, distilled water saturated with illum- 

 inating gas, 15 minutes; No. 7, illuminating gas, 30 minutes, roots ex- 

 posed; No. 8, distilled water saturated with illuminating gas, 30 minutes; 

 No. 9, chloroform vapor, 30 minutes, roots exposed; No. 10, 4 per cent 

 chloroform in water, 30 minutes; No. 11, 4 per cent ether in water, to the 

 end of the experiment; No. 12, 10 per cent ether in water, 30 minutes; 

 No. 13, distilled water saturated with illuminating gas, to end of experi- 

 ment; No. 14, distilled water saturated with illuminating gas, 30 minutes 

 (frequently saturated) ; No. 16, control — roots exposed 30 minutes under 

 bell jar; No. 17, control — roots exposed 30 minutes under bell jar; No. 18, 

 control — roots placed directly into distilled water. The percentages given 

 above refer to volume-per cent. The plants were 37 days old when treated. 

 The first reading was made after the roots had been in distilled water 30 

 minutes (No. 10, 36 minutes). In all cases treatment preceded placing of 

 the roots in distilled water (conductivity of which was determined except in 

 the cases of Nos. 11, 13, and 18). In culture 3, 17cc. of the initial 25cc. 

 of ether remained at the end of the 30-minute exposure; in culture 9, 23.5cc. 

 of the initial 25cc. of chloroform remained. 



