﻿OSTERHOUT— PERMEABILITY 



Experiments with chloral hydrate gave results very similar 

 to those obtained with chloroform, the corresponding effects 

 being produced in both cases by approximately the same 

 percentage concentrations, 8 that is, chloral hydrate o.i per cent 

 (=0.006 M) acts similarly to chloroform 0.1 per cent by volume 

 (=0.0128 M). 



The experiments with alcohol lead to somewhat different results. 

 In the first place, alcohol is not as toxic as ether, chloroform, or 

 chloral hydrate, and higher concentrations must be used to pro- 

 duce the same effects on permeability. In sea water containing 

 alcohol 0.051 M or 2.955 per cent by volume (the solution being 

 renewed every 15 minutes) the results were much the same as in 

 0.099M ether (the solution being renewed every- 5 minutes), 

 except that the rise in resistance took place more slowly, sometimes 

 occupying 30 minutes or more. It was found that 0.2385M or 

 13.875 per cent by volume is decidedly toxic. 



An interesting feature of the results with alcohol is that the 

 increase of permeability is reversible. If the increase be carried 

 too far it is not reversible (or to a much smaller extent) ; in the first 

 experiments this condition was unintentionally realized and lead 

 the writer to suppose that alcohol behaves like ether. The course 

 of a typical experiment is shown in table VII and fig. 6. The 

 tissue was first placed in a mixture containing 970 cc. sea water-f- 

 30CC. Squibb's absolute alcohol+about 15CC. concentrated sea 

 water. This mixture had the conductivity of sea water; the con- 

 centration of alcohol was o . 05 1 M (2 .96 per cent by volume) . The 

 net resistance rose from 800 to 880 ohms in the course of 40 minutes. 

 The tissue was then placed in sea water containing o . 2385 M alcohol 

 (13.875 per cent by volume), and in the course of 20 minutes the 

 resistance fell to 700 ohms. The tissue was then placed in sea 

 water and the resistance again rose to 800 ohms. 



The facts that recovery occurs in alcohol, and that irregular 

 fluctuations are often observed in experiments on recovery 

 from ether, suggest that the difference between the behavior 



