A definition of this kind will cover 99 per cent. of all experiments. The extreme pro-vivisectionist may protest that the definition brings into prominence the more painful operations; yet for the majority of us the only ground for challenging the practice at all is the pain, amounting to torment in some cases, which vivisection may involve. They are rare, some one says. But how do we know? The doors of the laboratory are closed. Of practices secretly carried on, what can we know? That every form of imaginable torment has at some time been practised in the name of Science, we may learn from the reports of experimenters themselves, and from the writings of men who have denounced them. It was Dr. Henry J. Bigelow, of Harvard University, the most eminent surgeon of his day, who declared that vivisection sometimes meant the infliction of "the severest conceivable pain, of indefinite duration," and that it was "a torture of helpless animals, more terrible, by reason of its refinement, than burning at the stake." Is the above definition of vivisection stronger than is implied by this assertion of Dr. Bigelow? We need constantly to remember that vivisection is by no means a simple act. It may indicate investigations that require no cutting operation of any kind, and the infliction of no pain; or, on the other hand, it may denote operations that involve complicated and severe mutilations, and torments as prolonged and exquisite as human imagination can conceive. Experiments may be made, in course of researches, of very great interest and importance to medical science; and, on the contrary, they may be performed merely to demonstrate phenomena about which there is no doubt, or to impress on the memory of a student some well-known fact. They may be performed by men like Sir Charles Bell, who hesitated to confirm one of the greatest physiological discoveries of the last century, merely because it would imply a repetition of painful experiments; and they may be done by men like Magendie, who declared of his mutilated and tormented victims, that it was "DROLL to see them skip and jump about." It is because of all these differences that the majority of men have an indefinite conception of what they approve or condemn. The advocate of unrestricted vivisection sometimes tells us that experimentation implies no more pain than the prick of a pin, and that its results are of great utility to the human race; the antivivisectionist, on the other hand, may insist that such experimentation means inconceivable torment without the slightest conceivable benefit to mankind. Both are right in the occasional significance of the word. Both are wrong if one meaning is to answer for all varieties of experimentation upon living things.