VOL. LXX.] PHILOSOPHICAL TRANSACTIONS. 655 



some animals to be here and there transparent, especially towards the edges. 

 The pulmonary air was very visible through the external membrane: I have 

 examined it with a microscope, and have been able to distinguish very well the 

 small pulmonary bladders, streaked with vessels for the most part without blood. 

 Great as this alteration is in so important a viscus, I could not persuade myself, 

 that it could alone produce so great and instantaneous a disorder, and that the 

 whole force of the poison exerted itself only on the blood and lungs. There was 

 indeed the instance of the poison of the viper, which produces something 

 similar; but then this poison produces a kind of general coagulum in the blood 

 itself, which certainly is not observable from American poison. 



In an inquiry so important, and at the same time so obscure, I thought I 

 ought to have recourse to experiment itself, and to examine the effects of the 

 American poison when introduced immediately into the blood. For this purpose 

 I made use of the same method which I had before employed for introducing the 

 poison of the viper into the blood of the jugular. I used a turn-cock of glass, 

 bent at the point, instead of a small syringe. With this cock I took up the 

 American poison dissolved in water, and then opening the jugular vein thrust 

 the point into it. As the method of making this sort of experiments has been 

 before described in my treatise on the poison of the viper, I think it unnecessary 

 to give a particular description of it here. The experiment is so conducted, that 

 the poison enters the blood by the jugular without touching any cut part of the 

 vessels, not even those of the jugular itself. 



For the first experiment I put into the glass syringe 4 drops of the poison 

 dissolved in water; the quantity of poison in the 4 drops could hardly amount to 

 4- a grain. I introduced the crooked end of the syringe into the jugular of a 

 large rabbit; but in the act of pushing in the piston, which was not close enough 

 fitted to the bore of the syringe, the poison returned backward, which made me 

 say to the persons who were present, that the experiment had failed; hut I was 

 surprized when they answered me, that the animal was already dead. I believe 

 there were not 10 seconds between the moment in which I saw the poison turned 

 back, and that of my being told that the animal was dead, as in fact it was. I 

 cannot say what quantity of poison was introduced into the blood; there must 

 have entered a sufficient quantity, as the animal was killed; but had it not been 

 for that circumstance, I should have judged, from the quantity returned back, 

 that none at all had entered the jugular. The animal was so dead, that there 

 appeared no signs of respiration, and the whole body was more pendent and 

 flaccid in all its parts than is usual with animals that have been long dead. The 

 death of this animal followed so close on the introduction of the poison, that the 

 interval of time seemed quite insensible : it appeared to take place much quicker 

 than in the case of the poison of the viper, introduced into the blood in the same 

 manner. 



