700 DRS CRUM BROWN AND FRASER ON THE CONNECTION BETWEEN 



difficulty in jumping, and the anterior extremities were somewhat feeble, for they 

 could not properly support the chest. In ten minutes, progression was accom- 

 plished by vigorous pushing movements of the posterior extremities, the loss of 

 power being so decided that jumping was impossible. In twenty minutes, the 

 frog lay on the abdomen and chest, but still the condition was not one of complete 

 flaccidity, for the posterior extremities were flexed, and retained their proper 

 tone, while the anterior partially supported the head and upper part of the chest. 

 At this time, the respiratory movements were confined to the muscles of the 

 throat, and reflex contractions of a vigorous character followed slight irritations of 

 the skin. In thirty-five minutes, the paralysis was still more decided, for irrita- 

 tion now produced merely a series of interrupted and weak movements in the 

 extremities ; but, otherwise, the frog was in much the same state as that last 

 noted. It continued thus for other twenty minutes, when the paralysis became 

 less severe. A normal posture was assumed, and, by-and-by, vigorous voluntary 

 movements were performed. In about two hours after the administration, the 

 frog was in a normal condition. 



It is of interest to observe that these marked symptoms were produced by a 

 dose equivalent to only the ^woth °f the weight of the frog, while such a 

 dose of sulphate of atropia produces no obvious effect in frogs. 



Experiment XXXVII. — We injected under the skin at the right flank of a 

 frog, weighing 407 grains, one-twentieth of a grain of sulphate of methyl-atro- 

 pium, dissolved in four minims of distilled water. Very soon after, the move- 

 ments were performed with some difficulty ; and in five minutes, the anterior 

 extremities were sprawling, and the frog was unable to jump. In eleven minutes, 

 the frog was in a flaccid state on the abdomen, chest, and lower jaw; and but 

 feeble reflex contractions could be excited. In fifteen minutes, the reflex function 

 was suspended, and all respiratory movements had disappeared. In twenty-five 

 minutes, a sciatic nerve was exposed and subjected to galvanic stimulation, but 

 no muscular contractions were thereby produced, although direct galvanic stimu- 

 lation of the muscles caused vigorous contractions. The cardiac impulse was at 

 this time ascertained to be pretty strong, and the beats at the rate of thirty-two 

 per minute. During the two following days, the frog remained in this condition. 

 On the fourth day, however, it was found that the motor nerves had recovered 

 their conductivity, but still the reflex function of the spinal cord was suspended. 

 On the fifth day, the latter function was again present, and, indeed, the action of 

 the poison had now so far disappeared that the frog had resumed a normal 

 posture, and jumped freely when stimulated. There was no symptom whatever 

 on the following day. 



The dose given in this experiment w r as equivalent to the ^iV^th of the weight 

 of the frog used. To produce complete paralysis of the motor nerves for more 

 than two days with sulphate of atropia, it is necessary to exhibit a dose of 



