38 



Scientific Proceedings (102). 



O2 and CO2 between the alveolar air and the blood sufficiently to 

 cause real distress. Relief followed the discontinuance of digitalis 

 and the administration of belladonna. 



Conclusion. — In this case of auricular fibrillation digitalis did 

 not improve the circulation because it inrceased vagus affects 

 which diminished the O2 and CO2 interchange between alveolar 

 air and blood. 



21 (1481) 



The action of camphor on the central nervous system of the squid. 



By A. R. Moore. 



[From the Physiological Laboratory of Rutgers College, and the 

 Marine Biological Laboratory, Woods Hole, Mass.] 



Newly hatched squid (Loligo pealii) if put into a solution of 

 camphor gum in sea water, 1/10 saturation, show characteristic 

 mantle spasms, involving play of the chromatophores, after a 

 latent period which is about 40 seconds at 24 0 C. This effect, it 

 has been shown, is due to the action of camphor on the stellar 

 ganglia. 1 In appearance, camphor spasms are indistinguishable 

 from those caused by nicotine. 2 The difference does not lie in the 

 character of the response of the end organs, muscles and chromato- 

 phores, but in the locus and the nature of neuronic excitation. 



The value of the temperature coefficient Q i0 for the action of 

 camphor, based on the lengths of the latent periods, is 2.4. The 

 function connecting the velocity of the reaction with the concen- 

 tration of the drug is, for camphor, expressed by v = kC* in 



which v = : — — C = concentration, and k is a constant 



latent period 



whose value is approximately .75. 



The camphor spasms soon pass off and the animals lie inert 

 with chromatophores relaxed. This is not due to paralysis of the 

 end organs for the reason that they may again be thrown into 

 activity by treatment with strychnine or nicotine. The absence of 

 any interference between the action of nicotine and that of cam- 

 phor may be demonstrated by the following experiment. Let 



1 Moore, A. R., Proc. Nat. Acad. Sc., 1917. Ill, 598. 

 3 Moore, A. R., J. Gen. Physiol., 1919, I, 505. 



