the Action of po'iso77S on the Animal System. 27^ 



healino: art. This consideration, I slioukl hope, will be 

 rcgardid as a sufficient apology for my pursuing a mode 

 of inquiry !)y n)eans of cxptrimenls on brute animals, of 

 which we migiu well question the propriety, if no other 

 purpose were to be answered by it than the gratification of 

 curiosity. 



In my former comnmnieation on this subject, I entered 

 into a detailed account of the majority of my experiments. 

 This I conceived necessary, because in the outset of the 

 inquiry I had been led to expect that even the same poisoa 

 nnght not always operate precisely in the same manner ; 

 but I have since had abundant proof, that in essential cir- 

 cumstances there is but little variety in the effects pro- 

 duced bv poisons of any descrijuion, when employed on 

 animals of'the same, or even of different species, beyond 

 what may be referred to the difference in the quantity or 

 mode of application of the poison, or of the age and power 

 of the animal. This will explain the reason of my not 

 detailing, in the present communication, so many of the 

 individual experiments from which my conclusions are 

 drawn, as in the former; at the same time I have not been 

 less careful to avoid drawing general conclusions from only 

 a limited number of laets. Should these conclusions prove 

 fewer, and of less importance than might be expected, such 

 defects will, I trust, be reearded with indulgence, at least 

 by those who are aware of tlie difficulty ot conducting a 

 series of physioloijica! experiments ; of the time which 

 they necessarily occupy ; of the numerous sources of fallacy 

 and failure which exist ; and of the labori(His attention to 

 the minutest circumstances, which is in consequence ne- 

 cessary in order to avoid being led into error. 



II. Experiments luitJi the IVoorara, 



In a former experiment, 1 succeedeil in lecovering an 

 animal, which was apparently dead from the influence of 

 the essential oil of bitter almonds, by continuing respira- 

 tion arlifieinllv until the impression of the poison upon the 

 brain )iad cease*l ; but a sinnlar experiment on an animal 

 under the influence of the woorara wa-; not attended with 

 the same success. Some circumstances led me to believe, 

 that the re-^ull of the experiment with the woorara might 

 have been different, if it had been made with certain pre- 

 cautions ; but I was unable at that time to repeat it, in 

 consequence of my stock of the poison being exhausted. 

 J have since, however, lieen able to procure a fresh supply, 

 and I shall relate two experiments which 1 have made with 

 S4 it. 



