35O RALPH S. LILLIE. 



ally lose irritability and conductivity in an oxygen-free atmo- 

 sphere, or in cyanide solutions of considerable concentration 

 (Dontas) j 1 while the desensitizing effects of anaesthesia are rapid 

 and complete. That the two effects are essentially different is 

 further shown by the difference in the rate of recovery, which is 

 much prompter in the case of anaesthesia. Apparently narcosis 

 may decrease the oxidations in resting nerve trunks, as indicated 

 by the output of carbon dioxide; this is seen in the experiments 

 of Tashiro and Adams cited above, but the effect is compara- 

 tively slight and probably unconnected with the loss of irrita- 

 bility, since, as just seen, the nerve retains irritability in cyanide 

 solutions for a long time. Compare also Winterstein's results, 

 about to be described. Other similar instances are ciliary move- 

 ment and protoplasmic rotation, both of which are only gradually 

 checked by lack of oxygen or by cyanide, but instantly by 

 narcotics. Recently Winterstein 2 has shown that the reflex 

 irritability of the frog's isolated spinal cord may be entirely 

 lost under anaesthesia without affecting the general oxidation- 

 rate of the tissue; in fact during alcohol narcosis there was a 

 slight but regular increase in oxygen-consumption. The nar- 

 cotized cord differs from the non-narcotized in one chief respect; 

 in the normal and incompletely narcotized cord stimulation 

 causes increased oxygen-consumption; but during complete nar- 

 cosis no such effect is seen; the oxygen-consumption during 

 stimulation is the same as in the resting non-narcotized cord. 

 Oxygen is, however, essential for the normal irritability of the 

 cord ; complete recovery from narcosis requires not only removal 

 of the anaesthetic but also the presence of free oxygen. There 

 may, however, be partial recovery even in the absence of oxygen. 

 These facts illustrate how important oxygen is for the normal 

 activity of the nerve-cell; but they also show that, given a 

 supply of free oxygen, the consumption in the normal resting 

 cord may be the same as in the narcotized cord. If narcosis 

 were simply asphyxia, such a result would be inexplicable. A 

 further fact inconsistent with the "asphyxia hypothesis" of 

 narcosis is that after a narcosis lasting for days (9 days in one of 



1 Dontas, Arch. f. exp. Path. u. Pharm., 1908, Vol. 59, p. 430. 



2 Winterstein, Biochem. Zeitschr., 1914, Vol. 61, p. 81. 



