THE ACTIONS OF PHYSOSTIGMA AND ATROPIA. 



601 



results obtained when the administration of atropia was effected five minutes 

 after that of physostigma, then, those obtained when the administration of atropia 

 was effected ten minutes after that of physostigma, and so on until a period is 

 arrived at which is too prolonged to permit any dose of atropia to counteract 

 successfully the dose of physostigma invariably administered in this series. 



The range of the doses of sulphate of atropia that are able successfully to 

 counteract one and a half times the minimum-lethal dose of sulphate of physo- 

 stigmia, when the administration of the former substance was effected fine 

 minutes after that of the latter, has already been ascertained by experiments 

 contained in the second series. It was shown by these experiments (p. 593) that 

 this range extends from the one-twentieth of a grain to two grains and one 

 tenth. Death was found to occur when the dose of sulphate of atropia was so 

 small as three one-hundredths of a grain, and also when it was so large as two 

 grains and three tenths. It will be observed that this range is smaller than 

 that which is obtained when the two substances are simultaneously administered, 

 for in the latter case it extends from the one twentieth of a grain to three 

 grains and three tenths. 



In the experiments where the sulphate of atropia was administered ten 

 minutes after one and a half times the minimum-lethal dose of sulphate of 

 physostigmia, the following results were obtained : — 



Experiment 261. — With 0*05 grain of sulphate of atropia, death occurred. 



recovery 



recovery 

 „ „ recovery 



recovery 

 grains „ „ recovery 



recovery 

 „ „ recovery 



recovery 

 „ „ death 



„ „ death 



From these experiments it is seen, that when sulphate of atropia is admin- 

 istered ten minutes after sulphate of physostigmia, any dose of the former 

 substance ranging from three tenths of a grain to two grains and a half, is able 

 to prevent the fatal effect of one and a half times the minimum-lethal dose of the 

 latter substance. The range is, again, a more limited one than that obtained by 

 simultaneous administration. It is, however, a somewhat more extended one 

 than that obtained where the atropia is administered five minutes after the physo- 

 stigma. and the greater extension is due to the maximum successfully antagonising 

 dose of sulphate of atropia being considerably greater when the administration 



VOL. XXVI. PART III. 7 R 



Experiment 262-a. , 



, 0-3 



Experiment 263-a. , 



, 0-5 



Experiment 264-a. , 



, 1- 



Experiment 265-a. , 



, 15 



Experiment 266-a. , 



, 2- 



Experiment 267-a. , 



, 2-3 



Experiment 268-a. , 



, 24 



Experiment 269-a. , 



, 2-5 



Experiment 270. , 



, 2-7 



Experiment 271. , 



, 3* 



