408 Prof. Christison on the Poisonous Properties of Hemlock, 



APPENDIX OF SELECTED EXPERIMENTS. 



I. Experiments with Conia. 



Exp. I. Six drops of conia were allowed to fall into the back of the throat of a 

 young active puppy ten weeks old. In thirty seconds there was sudden convul- 

 sive respiration, and some stiffness of the hind-legs, immediately followed by great 

 feebleness of these legs. In a few seconds the fore-legs also became very feeble. 

 In sixty seconds from the time the poison was introduced, the breathing ceased. 

 Slight convulsive tremors followed for a single minute more. 



In three minutes the chest was laid open. The intestines were moving and the 

 heart pulsating briskly. In fifteen minutes the auricles of the heart ceased to con- 

 tract spontaneously, but they began again to contract when the pericardium was 

 slit open. In eighteen minutes, when all spontaneous motion had ceased, galvanism 

 directly applied to the right ventricle excited feeble, tremulous contraction. The 

 blood then discharged from the heart flowed out quite fluid, equally dark from both 

 sides, and coagulated firmly afterwards. In eight minutes the diaphragm, as well 

 as the serratus magnus muscle, contracted briskly when a galvanic current was trans- 

 mitted from their respective nerves to their substance ; and the latter also contracted 

 when its nerve was either pinched or galvanized by touching it with both poles of 

 the pile ; not so, however, the diaphragm. The vermicular movement of the intes- 

 tines was instantly arrested by allowing a drop of conia to fall on a loop of the gut, 

 but only in the part touched, which also contracted much, and became greyish- 

 white. 



Exp. II. A small aperture was made into the peritoneal sac of an active puppy 

 of the same litter with the last, and three drops of conia were introduced completely 

 within the peritoneum by a pipette. Instant acute expression of pain followed. For 

 some little time there was no visible effect, and it pursued a rabbit briskly up and 

 down the room. But in two minutes it suddenly stopped, and the hind-legs became 

 stiff. Then the breathing became laboured, and the hind-legs feeble. In three mi- 

 nutes and a half there was great feebleness of the whole limbs, so that it rose with 

 difficulty. In four minutes and a half it fell forward in a paralytic state on trying 

 to walk ; and the limbs were completely palsied. In five minutes the respiration 

 was diaphragmatic only, the chest being perfectly flaccid. The sensibility was still 

 quite entire, the eyes turning in the direction of one calling to it, and the countenance 

 expressing uneasiness when the paws were squeezed. In seven minutes the breath- 

 ing was confined to feeble respiratory twitches, and the whole body became flaccid, 

 with occasional tremulous movement of the muscles of the trunk. In seven mi- 



