604 



DR THOMAS R. FRASER ON THE ANTAGONISM BETWEEN 



of three tenths of a grain of sulphate of atropia ; in the other, after the adminis- 

 tration of half a grain. 



From the experiments of this group we learn that the fatal effect of one 

 and a half times the minimum-lethal dose of physostigma can be prevented by 

 any dose between one-twentieth of a grain and two grains and one tenth of 

 sulphate of atropia, if it be administered within five minutes afterwards ; 

 by any dose between three tenths of a grain and two grains and one tenth of 

 sulphate of atropia, if it be administered within ten minutes afterwards ; and by 

 any dose between three tenths of a grain and one grain of sulphate of atropia, 

 if it be administered within fifteen minutes afterwards. 



(c) Experiments in which Atropia was administered before Physostigma. — 

 In the last group of experiments to be considered, the administration of atropia 

 preceded that of physostigma.* I shall, in the first place, describe those experi- 

 ments that were undertaken for the purpose of determining what range of 

 doses of atropia can successfully counteract one and a half times the minimum- 

 lethal dose of physostigma, when the former substance is given five minutes 

 before the latter. In Series ii. of this section, this range has already been 

 determined in the case of the extract of physostigma ; but it was considered 

 advisable also to perform with the sulphate of physostigmia a few experiments 

 in which this interval was observed, as it has been shown that the dose of this 

 substance adopted as the minimum-lethal is somewhat more powerful than the 

 dose of extract of physostigma adopted as such (p. 543). 



Experiments were accordingly performed, in which atropia in various doses 

 was administered Jive minutes before one and a half times the minimum-lethal 

 dose of sulphate of physostigmia. The doses of atropia given in each experi- 

 ment, and the results obtained, were as follows : — 



. Experiment 280. — With 001 grain of sulphate of atropia, death occurred. 

 Experiment 281-a. 

 Experiment 282-a. 

 Experiment 283-a. 

 Experiment 284-a. 

 Experiment 285. 

 Experiment 286. 

 Experiment 287. 

 Experiment 288. 

 Experiment 289. 



It is shown by these experiments that when sulphate of atropia is adminis- 

 tered five minutes before one and a half times the minimum-lethal dose of 

 sulphate of physostigmia, any dose of the former substance ranging from one 

 fiftieth of a grain to three grains and seven tenths is able to produce success- 



002 



>> 



recovery „ 



005 



» 



recovery „ 



3 "5 grains „ 



>> 



recovery „ 



37 



>5 



recovery „ 



39 



>J 



death „ 



40 



) 



death „ 



43 



>> 



death „ 



45 



>> 



death „ 



5" 



f) 



death „ 



Tabular Summary, Series iii. Table 3. 



