-PHYSOSTIGMA AND ATROPIA* 
this remarkable memoir, Dr. Fraser has shown how 
4 
with a kind of exactness which has hitherto been confined 
o purely physical inquiries. 
_ That an antagonism exists between the physiological 
action of atropia and that of the Calabar bean had been 
strongly indicated by Kleinwachter and by Bourneville.} 
Dr, Fraser has not only confirmed this, but has, by means 
of a series of nearly 500 experiments, traced the character 
and extent of this antagonism. 
communication is not to give an account of the matter of 
_ Dr. Fraser’s paper, but to explain shortly its method, we 
refer the reader interested in therapeutics to the paper 
itself for details. 
_ The experiments were performed on rabbits, of as 
Cy 
a 
le 
tract of Calabar bean that would otherwise have caused 
; death, Dr. Fraser proceeds to trace, by means of three 
_ series of experiments, the nature and extent of this anta- 
gonising action. 
__ It is scarcely necessary to state that this action is of a 
_ purely physiological character, the two drugs having no | 
chemical action upon one another. 
In describing these three series of experiments, we shall, | 
_ for the sake of shortness, refer to the three variable quan- 
tities mentioned above as follows :— 
«= The dose of sulphate of atropia measured in 
grains per 3 lbs. of rabbit. 
* “ An Experimental Research on the Antagonism between the Actions of 
Physostigma and Atropia.” By Thomas R. Fraser, M.D., Lecturer on 
Materia Medica and Therapeutics. Trans. R. S. E. xxvi. 129—713. 
ot Since the publication of Dr. Fraser’s preliminary note, Bourneville has 
_ published a series of experiments satisfactorily demonstrating the existence 
+ problems in experimental therapeutics may be treated | 
As the object of this 
| ditions of experiment may be varied. 
the dose of physostigma ; (2) the dose of atropia; and 
_ of this antagonism. 
4 
dition. The doses of the two poisons were administered 
in the form of aqueous solutions, by subcutaneous injec- 
tion. 
It will be at once seen that, if we assume all the rabbits 
to have been of the same size, age, and general condition,* 
there are three quantities by change of which the con- 
These are—(1) 
(3) the interval of time between the administration of the 
two doses. In the tabular summary of experiments, Dr. 
Fraser has noted in each experiment the effect on the 
pupils, on the heart’s action, on the respiration, on secre- 
tion and excretion, and on the action of the voluntary 
muscles. We shall, however, in this notice confine our- 
_ selves to the general result, viz., recovery or death. 
After proving, by means of upwards of 50 experiments, 
that the administration of small quantities of sulphate of 
nearly as possible uniform weight (about 3]bs.) and con- | atropia enables an animal to recover after a dose of ex- 
2 = The dose of extract of Calabar bean (or of sul- 
phate of physostigma) in units of 1°2 grain of ex- 
tract, or 0°12 grain of sulphate of physostigma, per 
3 lbs. of rabbit.f a 
y = Interval of time in minutes between the adminis- 
tration of the two substances, taken positive when 
the atropia, negative when the physostigma is ad- 
ministered first. 
In the first series, y=5 ; inthesecond, y= —5; andin 
* As a given dose of poiton affects a small animal more than it doesa 
larger one, the doses were, for the purposes of comparison, multiplied by the 
es aE 
factor weight of rabbit in pounds = ar Pte 
would have produced the same effect on a rabbit weighing 3lbs. This is 
almost certainly not a perfect mode of correcting for difference of weight ; 
; thus reducing them to the doses which 
| but as the correction is always small—the animals being selected of as near 
3 lbs. weight as possible—it may be assumed to be practically sufficient. 
+ This unit was chosen by Dr. Fraser as being the minimum dose pre- 
ducing death when no atropia was administered. 
