THE ACTIONS OF PHYSOSTIGMA AND ATROPIA. 



543 



Number of 

 Experiment. 



"Weight of 

 Rabbit. 



Actual Dose. 



Dose per 3 lbs. 

 Weight of Animal. 



Result. 



27. 



3 lbs. 8 oz. 



0-035 gr. 



0-03 gr. 



Eecovery. 



28. 



3 lbs. 1 oz. 



0-076 gr. 



0-075 gr. 



Recovery. 



29. 



3 lbs. 1 1 oz. 



0-1 gr. 



0-081 gr. 



Death, in about 33 minutes. 



30. 



3 lbs. 2 oz. 



0-1 gr. 



0-096 gr. 



Recovery. 



31. 



3 lbs. 1 oz. 



0-12 gr. 



0-117 gr. 



Death, in about 37 minutes. 



32- 



3 lbs. 5 oz. 



0-13 gr. 



0-117 gr. 



Death, in about 44 minutes. 



33. 



3 lbs. 4 oz. 



013 gr. 



0-12 gr. 



Death, in about 34 minutes. 



34. 



2 lbs. 14 oz. 



0-13 gr. 



0-13 gr. 



Death, in about 22 minutes. 



35. 



3 lbs. 6 oz. 



0-15 gr. 



01 3 gr. 



Death, in about 16 minutes. 



36. 



3 lbs. 4 oz. 



0-16 gr. 



0-147 gr. 



Death, in about 25 minutes. 



37. 



3 lbs. 



0-15 gr. 



0-15 gr. 



Death, in about 28 minutes. 



38. 



3 lbs. 3 oz. 



0-16 gr. 



0-15 gr. 



Death, in about 21 minutes. 



39. 



3 lbs. 2 oz. 



0-19 gr. 



0-18 gr. 



Death, in about 16 minutes. 



40 



3 lbs. 1 oz. 



0-18 gr. 



0-18 gr. 



Death, in about 19 minutes. 



From these experiments, it would appear that in rabbits the minimum lethal 

 dose of sulphate of physostigmia is a little less than 012 grain for every three 

 pounds weight of animal, or 04 grain for every pound. The experiment in which 

 death occurred after the administration of 0*08 grain per three pounds weight 

 (Expt. 29), must be regarded as an exceptional one, seeing that during it 

 the rabbit was in a violently excited state; and the constant energetic move- 

 ments that were made placed the animal in an unfavourable condition to resist 

 the toxic influence of a poison that materially embarrasses both the cardiac and 

 the respiratory functions. Still, even after excepting this experiment, the table 

 shows that 0'12 grain per three pounds is a dose rather in excess of the minimum 

 fatal. I have, however, adopted it as the minimum fatal dose ; and the ratio of 

 one to ten that is thereby obtained between corresponding lethal doses of 

 sulphate of physostigmia and extract of physostigma is a very convenient one, 

 and greatly facilitates the substitution of the one substance for the other in 

 doses credited with equal lethal activity. 



It may not be altogether unnecessary to point out that the results of these 

 determinations are applicable only to the special preparations with which they 

 have been obtained ; for the composition, and therefore the lethal activity, of 

 each of them varies somewhat in accordance with the processes followed in its 

 manufacture. 



Influence of Atropia on the Lethal Action of Physostigma. 



The minimum fatal dose for rabbits of the extract of physostigma and of 

 the sulphate of physostigmia having thus, with considerable accuracy, been 

 determined, the influence of atropia on the lethal action of physostigma formed 

 the next subject of examination. 



