THE ACTIONS OF PHYSOSTIGMA AND ATROPIA. 



583 



It is shown by this brief statement of the experiments with the minimum - 

 lethal dose of physostigma, that while one two-hundredth of a grain of sulphate 

 of atropia is a dose insufficient to prevent death, nine one-thousandths of a 

 grain is one sufficiently large to do so ; that any dose of sulphate of atropia 

 ranging within the wide limits extending from the nine one-thousandths of a 

 grain to five grains and one fifth is able to prevent the fatal effect of this 

 dose of physostigma ; and that if the dose of sulphate of atropia amount to 

 five grains and three-tenths, the region of successful antagonism is left, and 

 death occurrs. 



Experiments with One and a half times the Minimum- Lethal Dose of Physo- 

 stigma. — In the next place, experiments were made to determine what doses of 

 atropia are able successfully to counteract a dose of physostigma one and a half 

 times as large as the minimum-lethal.* The following results were obtained : — 



atropia, death occurred, 

 death 

 recovery 

 death 

 recovery 

 recovery 

 recovery 

 recovery 

 recovery 

 grains „ recovery 



recovery 

 recovery 

 recovery 

 death 



From these experiments, it appears that while three two-hundredths of a 

 grain of sulphate of atropia is a dose too small to prevent the occurrence of 

 death after a dose of physostigma one and a half times as large as the minimum 

 lethal, one-fiftieth of a grain is a dose sufficiently large to do so ; that doses of 

 sulphate of atropia ranging from one-fiftieth of a grain to four grains and one- 

 tenth are able successfully to counteract this dose of physostigma ; and that 

 death occurs when the dose of sulphate of atropia is so large as four grains and 

 three-tenths. In the presence of various causes of fallacy, which cannot alto- 

 gether be obviated, it is not surprising that results of an exceptional character 

 should occasionally be obtained. The occurrence of death in Experiment 

 91, where the dose of sulphate of atropia is one-fiftieth of a grain, may legiti- 



Experiment 88.— With 0-014 



Experiment 89. 



j> 



0015 



Experiment 90-a. 



55 



002 



Experiment 91. 



55 



0-02 



Experiment 92-a. 



55 



02 



Experiment 93-a. 



55 



003 



Experiment 94-a. 



55 



005 



Experiment 95- a. 



55 



0-05 



Experiment 96-a. 



55 



1-5 



Experiment 97-a. 



55 



2- 



Experiment 98-a. 



55 



26 



Experiment 99-a. 



55 



33 



Experiment 100-a 



55 



41 



Experiment 101. 



55 



43 



Tabular Summary, Series 1 , Table 3. 



