480 



DR T. R. FKASER ON SOME TJNDESCRIBED TETANIC SYMPTOMS 



this experiment, seven-twentieths of a grain of sulphate of atropia, administered 

 to a frog, weighing 372 grains, produced complete paralysis of the motor nerves 

 on the first and second days; tetanus on the third (slight), fourth, fifth, and sixth 

 days ; and stiff spasmodic movements on the seventh and eighth days. Complete 

 recovery had taken place on the tenth day. 



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Diagram 1.* 



In the diagram, the curve of paralysis, opj). 2 p s , &c, rises abruptly from the 

 line of normality, AB. The symptoms are those of paralysis only, until the curve 

 of spinal-stimulation, os x s 2 s 3 , &c, cuts that of paralysis between t 2 and £.,, after 

 the descent of the latter from the line of complete paralysis, CD. Tetanus 

 then becomes the predominant symptom. At first, its violence is considerably 

 checked by the coexisting paralysis ; but as the ordinates of the paralytic curve 

 diminish in length, while those of the tetanic curve increase, the tetanic symp- 

 toms gradually acquire greater prominence and force, until they reach their 

 maximum intensity between t s and t. a . They then, in their turn, also diminish. 



This diagram further shows how a paralytic and a spinal-stimulant (tetanic) 

 action may be coexistent, while the effects of only one of these are apparent. 

 Between o and t 2 , the symptoms are those of paralysis alone, because the spinal- 

 stimulant action is altogether masked by the complete paralysis ; between t 2 and 

 £ 8 , tetanic symptoms appear, because the paralysis is incomplete, and reflex 

 movements are therefore permitted to occur ; and between t 3 and t 5 , the spinal- 

 stimulant action, being but slightly checked by paralysis, manifests itself by 

 violent tetanic convulsions. 



The effects of this combined action on a mammal are graphically repre- 

 sented in Diagram 2. The experiment (Experiment LVIII.) I have selected 

 is one in which eight grains of sulphate of atropia in solution was injected 

 under the skin of a dog, weighing fifteen pounds. Slight paralysis was 

 observed at twenty minutes, and feeble spasms occurred at forty minutes ; they 

 together reached their maximum intensities at about seventy minutes ; and the 



* AB, line of normality, each division of which, ot v t,t 2 , t 2 f s , &c, represents a period of 

 twenty-four hours ; CD, line of complete paralysis ; op-yp 2 p 3 , &c, curve of paralysis ; os^s^ &c, 

 curve of spinal-stimulation (tetanus, &c.) ; ^p,, t 2 2^ 2 , &c., ordinates whose length roughly represents 

 the amount of the paralytic action ; t 1 s 1 , t 2 $ 2 , &c, ordinates whose length roughly represents the 

 amount of spinal-stimulant action. 



