484 



DR T. R. FRASER ON SOME UNDESCRIBED TETANIC SYMPTOMS 



In this diagram (Diagram 4), the curve of paralysis, op x p 2 p z , &c, does not at 

 any time rise to the level of the line of complete paralysis, CD ; whereas in the 



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Diagram 4.* 



diagram representing the effects of a fatal dose in a frog (Diagram 3), the curve 

 of paralysis very quickly reaches this line.f Accordingly, in this experiment, 

 the spinal-stimulant action, which was considerable, was not prevented from 

 manifesting itself, and spasms and tetanus coexisted with paralysis up to the time 

 at which death occurred. 



When a dose of atropia considerably below the minimum fatal, and just suffi- 

 ciently large to produce obvious effects on motility, is administered to a frog, the 

 effects are such as have been roughly delineated in the next diagram. 



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Diagram 5. J 



In a mammal the effect of such a dose would be represented by a diagram, 

 in which the differences between the ordinates of the paralytic and spinal- 

 stimulant curves are less than in the above. 



The symptoms being but slight in both cases, the ordinates of the curves are 

 very short ; and as the amount of paralytic action in atropia is greater than the 

 amount of spinal-stimulant, the area enclosed by the curve op^p^ &c, and the 



* AB, line of normality, each division of which, ot x , t$ v t 2 t z , &c, represents a period of ten 

 minutes ; CD, line of complete paralysis ; opjjp 9 p it &c, curve of paralysis ; os^Sg, &c, curve of 

 spinal-stimulation (tetanus, &c.) ; t t p v t 2 p 2 , &c, ordinates whose length roughly represents the 

 amount of the paralytic action ; t 2 s 2 , t s s 3 , &c, ordinates whose length roughly represents the amount 

 of the spinal-stimulant action. 



f It is probable that a stage of tetanus occurring subsequently to a stage of paralysis has never 

 been observed in mammals, after the administration of atropia, because a sufficiently large dose can- 

 not be administered without causing death while the paralytic effects are being developed. It is, 

 however, possible that separate paralytic and tetanic stages might be produced in mammals, if 

 artificial respiration were employed after the administration of a very large dose. 



X AB, line of normality, each division of which, ot v t t t s , t 8 t 12 , &c, represents a period of four 

 hours ; CD, line of complete paralysis ; op t p 8 p 12 , &c, curve of paralysis ; s^^, &c, curve of 

 spinal-stimulation (tetanus, &c.) ; t i p v t 8 p 8 , &c, ordinates whose length roughly represents the 

 amount of the paralytic action; t i s i> t 8 s 8 , &c, ordinates whose length roughly represents the amount 

 of the spinal-stimulant action. 



