ACTIOir OF POISONS ON THE ANIMAL SYSTEM. g5ft 



abundant proof, that in essential circumstances there is but little but the efFccti 

 variety in the effects produced by poisons of any description, "^ poisons dif- 

 when employed on animals of the same, or even of different ^^'' ^"^ ^'"'^' 

 species, beyond what may be /eferred 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 Hence fewer 

 not deLiiling, in the present communication, so many of the experiments 

 individual experiments from which my conclusions are drawn, ^^^ 

 as in the former : at the same time I have not been less care- 

 ful to avoid drawing general conclusions from only a limited 

 number of facts. Should these conclusions prove fewer, and 

 of less importance than might be expected, such defects will, 

 I trust, be regarded with indulgence, at least by those who are 

 aware of the difficulty of conducting a series of physiological DifRculty of 



experiments J of the time which they necessarily occupv ; of P^y^'"'"^'*^*^ 

 ,, /-,-,, , ^ .. . eiperinienti. 



the numerous sources of fallacy and failure which exis^t ; and 



of the laborious attention to the minutest circumstances, which 



is, in consequence, necessary, in order to avoid being led into 



errour. 



//. Experiments with the Woorara. 



In a former experiment I succeeded in recovering an ani- Artificial re- 

 ntal, which was apparently dead from the influence of the ^P""^?"" '"^'^°' 

 ■ 1 M r . • , , . . . . . \eTed an ani- 



essential oil or bitter ahnonds, by continuing respiration arti- mal from the 



licially until the impression of the poison upon the brain had P<>iso» of bit- 



, , . ., . . . 1 , . ter almonds : 



ceased ; but a similar experiment on an animal under the in- but not from 



fluence of the woorara v^ as not attended with the same sue- ^^^^ "^ woo- 

 cess. Some circumstances led me to believe, that the result 

 of the experiment with fhe 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 appa- yet ithasfinal- 

 rently dead from the woorara, was made to recover, notwith- lysucceeded 

 standing the functions of the brain appe.ired to be wholly sus- 

 pended for a very long period of time ; in the other, though 

 ultimate recovery did not take place, the circulation was main- 

 tained for several hours after the brain had ceased to perform 

 its office. 



S 2 Expe- 



