608 BR THOMAS R. FRASER ON THE ANTAGONISM BETWEEN 



Experiment 318. — "With an interval of 15 minutes, death occurred. 



Experiment 319. „ 20 



Experiment 320-a. „ 25 



Experiment 321-a. „ 30 



Experiment 322-a. „ 65 



Experiment 323. „ 65 



Experiment 324. „ 105 



Experiment 325-a. „ 105 



Experiment 326-a. „ 140 



Experiment 327-a. „ 170 



Experiment 328-a. „ 175 



Experiment 329. „ 180 



Experiment 330. „ 185 



Experiment 331. „ 200 



death 



recovery 



recovery 



recovery 



death 



death 



recovery 



recovery 



recovery 



recovery 



death 



death 



death 



It appears from these experiments, that when a dose of five grains of sul- 

 phate of atropia is administered before one and a half times the minimum- 

 lethal close of sulphate of physostigmia, death occurs if the interval of time be 

 one of fifteen minutes, or of twenty minutes ; that recovery generally occurs if 

 the interval be one included within the "wide limits extending from twenty-five 

 minutes to one hundred and seventy-five minutes (two hours and fifty-five 

 minutes) ; and that death again occurs if the interval be one so great as a 

 hundred and eighty minutes (three hours). In connection with these results 

 also, it is of interest to point out that in two experiments previously described, 

 where the same respective doses of sulphate of atropia and sulphate of physo- 

 stigmia were given, death occurred both when the two substances were simul- 

 taneously administered (Experiment 260) and when the atropia was adminis- 

 tered five minutes before the physostigma (Experiment 289). 



A very interesting and suggestive chain of events is therefore presented 1 y 

 the experiments in which five grains of sulphate of atropia was administered 

 in combination with one and a half times the minimum-lethal dose of sulphate 

 of physostigmia. For it is seen that certain actions produced with sufficient 

 intensity to cause death when the two substances are simultaneously adminis- 

 tered, lose the power of doing so when the atropia is administered at an interval 

 of twenty-five minutes before the physostigma ; while the now unobscured 

 counteraction of the lethal effect of this dose of physostigma, which makes this 

 loss perceptible, persists till the interval is increased to three hours. 



These various changes are no doubt caused by there being a progressive 

 increase followed by a decrease in the intensity of certain of the actions 

 that are produced by this dose of atropia. The progressive increase is 

 probably influenced to some extent by the rate at which the atropia is 



