Narcosis and Temperature 



259 



122 (2082) 



Narcosis and temperature. 



By M. E. COLLETT. 



[From the University of Buffalo, Buffalo, New York.] 



If the lipoid theory of narcosis is true, we should expect to 

 find the narcotic power of a substance and its oil water partition 

 coefficient similarly affected by changes in temperature. Thus, 

 benzamide and salicylamide should increase in efficiency as the 

 temperature falls, while chloral hydrate should increase as the 

 temperature rises. The experiments here reported were made in 

 1921-22 at Woods Hole (M. B. L.) and at the University of 

 Buffalo in order to test the question, since recent literature has 

 reported rather conflicting evidence. 



My experiments showed that in some cases, (swimming move- 

 ments of Loligo and Gonionemus, and heart-beat of Perophora) 

 the rule holds at least over the range of concentrations tested. 

 In other instances (swimming of toad and frog tadpoles, Bdel- 

 loura and Arbacia gastrulse) the rule holds for chloral hydrate 

 at all concentrations, but for benzamide and salicylamide only 

 at low concentrations. In still other cases (cilia of Nereis gas- 

 trulse, gill cilia of Venus and Pec.ten, tentacles of Metridium, 

 chromatophores of Loligo) the rule holds only for chloral hy- 

 drate; benzamide and salicylamide, instead of increasing in ef- 

 ficiency as temperature falls, regularly decrease at all concen- 

 trations tested. With a few tissues (hearts of Nereis and 

 Limulus, chromatophores of Fiindidus, cilia of Arenicola lar- 

 vae) a fall in temperature increases the efficiency of chloral 

 hydrate as well as of salicylamide and benzamide; but as these 

 tissues are easily narcotized by cold alone, the results are of 

 doubtful significance. 



From these experiments it would seem that the lipoid theory 

 of narcosis holds true, at least for many tissues, provided that 

 dilute solutions are used. With stronger solutions other factors 

 than lipoid solubility may enter in and so cloud the results. 



