Conductivity of External Solution. , Conductivity of External Solution. 
Stiles and J ergensen.— Studies in Permeability. IV. 63 
It might be urged that in the case, for instance, of isobutyl alcohol, con- 
centrations below 0*3 m. produce an exosmosis not differing greatly during 
the first 24 hours from that produced by distilled water, while solutions 
above that concentration produce considerably greater exosmosis, and that 
Time in hours. 
Fig. 9. Exosmosis of electrolytes from potato in solutions of i'soamyl alcohol of various 
concentrations. 
2. 4 6 9 to 12. 14 to 19 20 
Time in hours. 
Fig. 10. Exosmosis of electrolytes from potato in solutions of a secondary octyl alcohol 
of various concentrations. 
therefore 0*3 m. is the critical concentration. But there is no reason why the 
exosmosis during 24 hours should be chosen rather than that during any 
other time. If 48 hours were chosen, a different critical value would be 
found ; and if a shorter time, as for example 4 hours, were selected, a value 
