THE ACTIONS OF PHYSOSTIGMA AND ATROPIA. 613 



developed in the experiments where recovery followed the administration of the 

 smaller of the doses of sulphate of atropia that were given simultaneously with, 

 after, and before the dose of physostigma, or of a large dose of sulphate of 

 atropia at a long interval of time before the physostigma. These effects were 

 also produced in a marked form when death followed the administration of the 

 smaller of the doses of sulphate of atropia that were given simultaneously with, 

 and five minutes after and before the dose of physostigma, and when death 

 occurred where sulphate of atropia in somewhat large doses was given before 

 physostigma at too prolonged an interval of time to admit of successful anta- 

 gonism. 



Such, in general terms, were the characters of the symptoms in different 

 portions of the regions of recovery and death. The data for a more complete 

 analysis of these symptoms are contained in the Tabular Summary: in this 

 very general analysis, I have, with regard to the region of recovery, contented 

 myself with showing that the symptoms produced when atropia successfully 

 counteracts the lethal effect of physostigma vary greatly, according to the con- 

 ditions of administration. Successful antagonism is not necessarily accom- 

 panied with any special class of symptoms. It may be attended by a greater 

 prominence of the effects of atropia, but the same is true also of those of physo- 

 stigma. And, further, it does not appear that any special action belonging to 

 one or other substance requires to be obviously or prominently produced, in 

 order that the antagonism shall be successful. 



It is almost unnecessary to add, that the experiments in which recovery 

 occurred differed much from each other in the severity of their symptoms. In 

 many experiments the animal was only slightly affected, and there was no 

 reason at any time to anticipate a fatal result ; in others, however, symptoms 

 of a very serious character were developed, and in several cases it was for a 

 long time a matter of doubt whether the animal would recover. 



Combined Representation of the Three Series of Experiments. — In the three 

 series of experiments that have now been described, I have demonstrated the 

 limits of antagonism between atropia and physostigma, — firstly, when atropia 

 is administered five minutes before physostigma ; secondly, when atropia is 

 administered five minutes after physostigma ; and thirdly, when atropia in 

 various doses is administered at various intervals of time before and after 

 one and a half times the minimum-lethal dose of physostigma. 



In each series of experiments, of the three quantities (namely, dose of 

 physostigma, dose of atropia, and interval of time between the administration 

 of the substances) only two vary, and the results of any one series may there- 

 fore be represented by a diagram constructed on a plane. Such diagrams have 

 been constructed, and were described when the several series of experiments 

 were being separately considered. 



VOL. XXVI. PART III. 7 U 



