188 INJURY, RECOVERY, AND DEATH 



A series of investigations on chloroform gave similar 

 results, the chief difference being that chloroform is 

 much more toxic, and that the concentration necessary 

 for long continued decrease of permeability is much 

 lower, being about 0.05% by volume (or 0.064 M). This 

 is evident from Fig. 82, which shows the results of an 

 experiment with a mixture containing 999.5 cc. sea water 

 + 0.5 c.c. chloroform + 0.25 c.c. concentrated sea water 

 (this mixture had the same conductivity as sea water). 

 In this experiment the solution was renewed every 5 min- 

 utes during the first 80 minutes, and every 15 minutes 

 thereafter. j : ^ 



If we increase the concentration of chloroform to 

 0.1% by volume (=0.0128 M), the result is quite similar 

 to that obtained with 0.293 M ether. This is shown in 

 Fig. 82, which gives the results of an experiment contain- 

 ing 999 c.c. sea water + 1 c.c. chloroform + 0.5 c.c. concen- 

 trated sea water (this mixture had the conductivity of 

 sea water). 6 The solution was renewed every 5 minutes 

 during the first 80 minutes, after which it was kept in 

 sea water. There is no indication of recovery after the 

 tissue is replaced in sea water. 



Experiments with chloral hydrate gave results very 

 similar to those obtained with chloroform, the corres- 

 ponding effects being produced in both cases by 

 approximately the same percentage concentrations, 7 

 that is, chloral hydrate 0.1% (=0.006 M) acts similarly 

 to chloroform 0.1% by volume (=0.0128 M). 



8 Stiles and Jorgensen (1914) report a decrease of resistance as the 

 result of exposure to chloroform. See also Waller, A. D. (1919). 



7 No effort was made to find the exact percentages which are required 

 to produce given effects, as this was not the primary object of the investi- 

 gation. The actual concentration of chloral hydrate may have been 

 somewhat lower than those given, owing to the presence of water in the 

 chloral hydrate. 



