PRODUCED BY ATROPIA IN COLD-BLOODED ANIMALS. 



481 



spasms ceased at one hundred minutes, while the paralysis continued until about 

 one hundred and twenty minutes. The dog recovered perfectly. 



pi 



p2_ 



/»—-—" : 



P9 

 Sir—-. P"> 



1----. jm 



--_ T>K 



A 



is 



u 



ts 



t6 



t7 



t'8 



f9 



tio 



til 



t'12 



Diagram 2.* 



In this diagram, the curve of paralysis, op^p v &c, leaves the line of normalit}^ 

 AB, before the curve of spinal- stimulation, the first symptoms being those of 

 paralysis. As the curve op x p 2 , &c, never attains the level of the line of com- 

 plete paralysis, CD, the paralytic action is never sufficiently great to prevent the 

 manifestation of the considerable spinal-stimulant action present. Although the 

 ordinates t 6 s 6 , £ ? s 7 , and t s s s , are considerably longer than the ordinates t b s b and 

 t 9 s g , the effects of spinal-stimulation are not proportionally greater at t 6 , t 7 , and 

 t s than at t b and t g , for the ordinates of the paralytic curves also are longer at the 

 former than at the latter times, reaching their highest point at about the same 

 time as those of the spinal-stimulant curve, and the spinal- stimulant action is, 

 accordingly, more masked about the time of its greatest intensity than at times 

 somewhat anterior and subsequent thereto. These curves, therefore, admirably 

 represent the effects that were observed, the convulsive symptoms having been 

 of nearly uniform intensity throughout the whole time of their occurrence. 



It has been taken for granted that the paralytic and spinal-stimulant actions 

 coexist in frogs after the administration of large doses of atropia. Some 

 evidence in support of this view may with propriety be given at this place. 



Experiment LIX. — In a frog, weighing 270 grains, the abdominal aorta was 

 ligatured immediately above its bifurcation into the two iliacs, and one-fifth of 

 a grain of sulphate of atropia, dissolved in four minims of distilled water, was 

 then injected under the skin at the right side of the thorax. Great impairment 

 of motility and other symptoms of atropia action had occurred in one hour, when 

 the observations were interrupted. 



On the following day — twenty-three hours after the administration — the frog 

 was lying on the abdomen, chest, and lower jaw, the anterior extremities being 

 perfectly flaccid, while the posterior were extended with the webs stretched. A 

 slight touch of the head caused a sudden attack of tetanus in the two pos- 

 terior extremities, which lasted for three seconds ; but it was impossible to 



* AB, line of normality, each division of which, ot v t^, « 2 < 3 , &c, represents a period of ten 

 minutes ; CD, line of complete paralysis ; opjV 2 'Pi> ^ c -> curve °* paralysis ; os-^s^s^ &c, curve of 

 spinal-stimulation (tetanus, &c.) ; t z p 3 , £ 4 p 4 , <fec, ordinates whose length roughly represents the 

 amount of the paralytic action ; t^^ t & s 5 , &c, ordinates whose length roughly represents the amount 

 of the spinal-stimulant action. 



VOL. XXV. PART II. 6 H 



