HYDE, ETC. : REFLEXES MODIFIED BY ALCOHOL. 2.35 



any effect at all, it is always a depressed or slowed response 

 to the stimulus, never causing a stimulating effect or shorter 

 reflex time. 



3. Doses less than 0.05 cc. of 15 per cent alcohol per 10- 

 gram frog produce no more change in the reflex time of some 

 of the cutaneous sensory organs than does the same dose of 

 Ringer solution. But a dose of 0.3 cc. of 30 per cent, though 

 seeming to stimulate by causing the frog to become irritable 

 and active, nevertheless produces a depression, or causes ir- 

 regular responses, or an entire loss of the reflex action. These 

 changes are observed in all of the spots experimented on ex- 

 cepting c, which is not influenced by weak doses. 



Moreover, these changes appear within ten minutes after 

 injecting the alcohol, and persist for from one to one and a 

 half hours. Doses above 0.3 cc. of 30 per cent to 0.6 cc. of 50 

 per cent produce within five minutes great changes in the 

 frog's behavior and appearance. Often the frog assumes a 

 ^at, sluggish and dazed attitude. Both the cutaneous and 

 higher reflexes are lost. The muscle tone is much decreased, 

 respiratory activity is not perceptible, and tetanic convulsions 

 may set in with the stronger doses. This condition may con- 

 tinue from one-half to two hours, but the reflex time of the 

 cutaneous sensory organs do not become normal again even 

 after twenty-four hours. 



Alcohol in quantities too small to produce any apparent 

 effect upon the frog has a decided influence upon the reflex 

 centers of some of the cutaneous sense organs, at least in so 

 far as to lower their irritability and reaction time. When these 

 centers are once affected by alcohol they do not become normal 

 again in their reflex responses for from six to twenty-four 

 hours. 



When the sensory spots fail to respond to a dose, they do so 

 immediately, and the depression increases, and is of longer 

 duration with increase in dose, until with 0.6 cc. of 50 per cent 

 alcohol, when all of the sensory spots, and the higher reflexes 

 as well, are either much prolonged or lost entirely for several 

 hours, the length of their absence depending upon the condition 

 of the frog experimented on. One cc. of 95 per cent alcohol is 

 toxic. 



It was observed that even small quantities exert a depress- 

 ing chemical action upon certain parts of the nervous system, 



3-Univ. Sci. Bull.. Vol. VII, No. 13. 



