INFLUENCE OF POISONS ON PROTOPLASM, ETC. HARRIS. 103 



The f^cneral inference from those and many similar ex- 

 periments was that, just as Waller had found aconitine had no 

 influence on ptyalin, a secretion enzyme, we found that 

 other deatlly alkaloids had only a slight retarding action on the 

 enzyme of internal respiration in the liver, hepatic reductase. 

 An alkaloidal poison is, therefore, not deadly because it com- 

 promise.s tissue respiration, at least on its inspiratory side, 

 as studied in the liver. 



Realizing that the narcotic poisons act characteristically 

 on the central nervous system, we next tried the effect of 

 deadly narcotic poisons on brain-juice. 



Six and a half minutes was the time required for cat 

 b.-ain-pulp to retluce the oxyhaemoglobin; the following table 

 shows that aconitine only added 2.5 minutes, hyoscine 3.5 

 and morphine 6.5 minutes respectiveh'. 



TABLE II. 

 Time in minutes required for reduction of mixtures con- 

 taining Ice of brain juice, 2cc of blood solution and Ice 

 of an aqueous solution of the poison having a no.-mal con- 

 centration of 



Poison 



0.1 



0.05 



0.001 0.00001 



Hyoscine hydrobromide 



Morphine sulphate 



9.5 

 13.0 







9.5 

 13 



Aconitine 





9.0 



8 5 



Caffeine citrate 



destroys 

 blood 





13 



Alcohol 





11.5 

 13 . 5 

 22 



12 



Ether 







13 5 



Chloroform 







12 











Alcohol, ether and chloroform were all much more in- 

 hibitory to the velocity of the tissue respiration of brain 

 than were such lethal poisons as hyoscine, morphine and aconi- 



