VEGETABLE POISONS. 77 



will, I trust, be regarded with indulgence, at 

 least by those who are aware of the difficulty of 

 conducting a series of physiological experiments, 

 of the time which they necessarily occupy, of the 

 numerous sources of fallacy and failure which 

 exist, and of the laborious attention to the mi- 

 nutest circumstances which is in consequence 

 necessary, in order to avoid being led into error. 



II. Experiments ivith the Woorara. 



In a former experiment, I succeeded in reco- 

 vering an animal which was apparently dead 

 from the influence of the essential oil of bitter 

 almonds, by continuing respiration artificially 

 until the impression of the poison upon the brain 

 had ceased ; while a similar experiment on an 

 animal under the influence of the woorara, was 

 not attended with the same success. Some cir- 

 cumstances led me to believe that the result 

 of the experiment with the woorara might have 

 been different, if it had been made with certain 

 precautions ; but I was unable at that time to 

 repeat it, in consequence of my stock of the 

 poison being exhausted. I have since, however, 

 been able to procure a fresh supply ; and I shall 

 relate two experiments which I have made with 

 it. In one of these an animal apparently dead 

 from the woorara was made to recover, notwith- 

 standing the functions of the brain appeared to 

 be wholly suspended for a very long period of 



