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present immediately to our senses, while experiment discovered to us 
their mode of existence under circumstances contrived by art,—not the 
result of natural necessity, but the act of one desirous of extending his 
knowledge. While we observe, we, as it were, watch Nature; when we 
experiment, we question her. Dr. Law remarked that nature or accident 
sometimes provided us with experiments on man, whose results were 
infinitely more satisfactory and more to be relied on than those deduced 
from the experiments, even the most artfully contrived, when made on 
inferior animals; that in the latter case the results were only applicable 
to human physiology when the animals experimented upon stood in 
very close zoological relation to man; and, therefore, the analogy could 
never be so complete as when nature or accident made man the subject 
of experiment. And, again, the sufferings of the animal the subject of 
experiment often so modified and affected the phenomena, that they could 
not be regarded as such as Nature would exhibit under less painful in- 
fluences. M. Groux’ case was one of those in which nature afforded us 
a facility of both seeing and hearing the actions of the heart more 
plainly than could be done under ordinary circumstances, when the 
walls of the chest were normally developed. A similar case to that 
of M. Groux occurred in a female in France, and who suffered as little 
inconvenience from it as M. Groux seemed to do, There was in her 
case, as in M. Groux’, a deficiency in the sternum, which allowed the 
heart’s action to be seen. She was beyond the age of thirty when she 
was the subject of observation. She was then in good health, actively 
engaged in laborious occupations, and had borne children. Dr. Law in- 
stanced, as an example of accident in the human subject supplying a 
most favourable opportunity of extending our physiological knowledge, 
the case of St. Martin, with whose history every physician was familiar. 
This man received a gun-shot wound which penetrated the chest and 
abdomen, wounding both the left lung and the stomach. He ultimately 
recovered, with a fistulous opening of the stomach, which communicated 
externally. Luckily for science, he became the servant of a physician, 
Dr. Beaumont, who knew how to avail himself of this precious oppor- 
tunity of investigating the actions of the stomach, and of observing the 
relative digestibility of different substances Which constitute our ordi- 
nary food, which he did by withdrawing them at various intervals of 
time, and seeing the time each required for its complete digestion. Dr. 
Beaumont’s observations made on St. Martin furnish us with the fullest 
information we possess on the process of digestion. Dr. Law urged, as an 
additional ground of preference for those natural and accidental experi- 
ments on the human subject, the reluctance of the British physician to 
experiment on inferior animals, except when impelled by imperious 
necessity,—a plea for which necessity, he felt, was only justifiable when 
these experiments held out a fair prospect of being directly instrumental 
to the attainment of a knowledge beneficial to mankind, and which could 
not be attained in any less objectionable way. The British physician 
participated in the sentiment of the distinguished Haller, who, when he 
would justify his experiments on animals, observes: —‘‘ Multa ipse peri- 
