NATURAL SCIENCES OF PHILADELPHIA. 371 



drug was given, unconsciousness occurred, from which the animal 

 could not be aroused. These experimenters must have been mis- 

 led by the paralysis making the expression of pain absolutely 

 impossible ; in this state of affairs the eyelids are drawn together, 

 giving still more the appearance of sleep ; or from their conia 

 being contaminated. 



The state to which I have just alluded as resembling sleep is 

 certainly not sleep, for when the abdominal aorta of a frog is tied 

 and conia injected into the anterior part of the body, paralysis 

 occurs anteriorly and the animal passes into this state of seeming 

 sleep, while posteriorly, voluntary movements continue until late 

 in the case, when paralysis of the spinal motor tract prevents all 

 movements. Had this been sleep, voluntary movements posteriorly 

 would have been absolutely impossible. After taking a grain and 

 a quarter of the alkaloid I once passed into this state of seeming 

 sleep ; that this was not sleep was shown by the circumstance that 

 consciousness was not lost, though the power over the various 

 muscles of expression was entirely gone for the time being. 



It is possible, however, that the brain becomes slightly clouded, 

 but not to the extent to produce unconsciousness. In inducing 

 complete repose of the muscular system, conia powerfully pre- 

 disposes the brain for sleep brings sleep within its reach, so to 

 speak, but there leaves it. If the imagination should happen to 

 be dull, the brain may accept the invitation, and sleep occurs. 



As the convulsions of couia-poisoning are certainly cerebral, I 

 shall now proceed to investigate this serious symptom, which 

 really signifies that death is imminent. 



Convulsions were early mentioned as symptoms of poisoning 

 by hemlock, but the cause of these convulsions had never been 

 determined. Christison (Trans. Roy. Soc. Ed., xiii. p. 383) im- 

 agined them to be due to a depressing action on the spinal cord, 

 while Damourette and Pelvette (Gaz. Med. de Paris, 37, 1870) 

 attributed them to excitation of the cord. 



It is very plain that the convulsions can be produced in but 

 five different ways : first, they may be spinal ; second, they may 

 be due to stimulation of the peripheral ends of the motor nerves ; 

 third, they may be caused by irritation of the peripheral ends of 

 the sensory nerves ; fourth, they may be muscular ; fifth, they may 

 be cerebral. 



That the convulsions of conia-poisoning are not due to irrita- 



