ON THE EFFECTS OF ACRID POISONS. 
219 
of the effect of any poisonous ingesta, and which are often 
quite as striking as those appearances which are met with when 
poisons have been known to be taken, we cannot but be sen¬ 
sible how fully medical men are justified when in cases of legal 
inquiry they hesitate to draw any positive conclusions from the 
state of the stomach itself, and lay the principal stress on the 
chemical analysis of its contents, as well as of that of the matter 
which has been rejected by vomiting, and of the articles of 
which those suspected of having been poisoned are known to 
have partaken. In this branch of inquiry great progress has 
been made of late years, and to no one in this country are we 
more indebted for it, than to Dr. Christison. Although it must 
not be expected that the report which the British Association 
has called for will throw that light on the morbid appearances 
produced by poisoning which will give to them a similar degree 
of certainty with that possessed by chemical analysis, yet I 
believe we may reasonably entertain the hope, that the various 
and multiplied experiments in which I know that my colleague 
on this occasion has been laboriously engaged will do much 
towards it. Some interesting conclusions appear to me to be 
pointed to, by the few instances of poisoning which have fallen 
under my own observation, as well as by the small number of 
experiments which I have as yet been able to make. These I 
will now proceed to lay before the Association, together with 
representations of the appearances observed, the fidelity of 
which does great credit to the artists by whom they have been 
produced. There are always painful feelings accompanying ex¬ 
periments on inferior animals, yet I trust that in making them 
we may be fully justified on principle, when the object in view 
promises to be an advantage to man, provided we are careful to 
seek the end in view with the least expense df life and with 
the least possible amount of suffering. I felt considerable diffi¬ 
culty in making choice of the animals to be the subject of these 
experiments, and have endeavoured as far as possible to take 
those lives which for other reasons it was either necessary or 
desirable to sacrifice. Another point to be kept in view in 
selecting the objects of experiments is, that the animals may 
be such, that the conclusions to be drawn from them may with 
a good degree of analogy be applied to man. Dogs have in 
general been selected for this purpose; and their size, their 
sufficient degree of tenacity of life, and their patience under suf¬ 
fering warrant this choice. I have made some attempts with 
cats, supernumerary and worthless animals of this species being 
more easily obtained than in the case of dogs ; but their extra¬ 
ordinary tenacity of life and the readiness with which they 
