Rabbits and dogs received injections of the blood of the immune horse. An hour after they received full doses of snake poison. They suffered no inconvenience at all; they were “protected,” or “rendered immune.” The next question was, “Will the antidote act on an animal after it has already been bitten by a snake?” The experiment was made. Rabbits were injected with snake poison. After a quarter of an hour they were on the point of death. A dose of the immune horse’s blood was now injected into each--in ten minutes they had completely recovered and were feeding. The means was thus found of preventing death from snake-bite. The protective horse-blood was properly prepared, and sent out at once to Cochin China and to India. It was there tried upon human beings who had been accidentally bitten by deadly snakes, and it proved absolutely effective; it saved the men’s lives. It is now used (wherever it can be obtained in time) as the sure antidote to snake-bite, though it is not at present possible to supply it whenever and wherever it is needed. That is an example, briefly told, of the experimental questioning of Nature--such as is pursued in the laboratories of medical men and physiologists. They do not perform haphazard experiments; but each experiment is so arranged as to give a definite answer to a definite question, leading to a large result. By no other process can knowledge of many things, which it is urgent for us to have, be obtained. We should have to wait centuries if we merely watched Nature, and hoped for some accidental circumstance to reveal the facts. What, after all, do we understand and mean by “pain”? It is not merely the sharp sting, and consequent shrinking caused by wounds and violence. That, we know well enough, is a beneficent arrangement by which men as well as animals are prevented from knocking themselves to pieces, and are driven into avoiding danger to life and limb. But “pain” includes, besides this, the anguish arising from the weary, fruitless struggle against disease and starvation, from the disaster to the household caused by the untimely death of its mainstay, from the slaughter of children by poisonous foods, and from the neglect of the laws of health of body and mind. Ignorance, the “curse of Hell,” is the cause of all suffering. Knowledge is the wing which takes us heavenward, and frees us from misery. I cannot put it better than in Shakespeare’s words. It is man’s destiny to diminish pain on this earth, and that not by timidly shrinking from and emotionally raving about the horrors of pain, but by facing them and deliberately accepting the responsibility of producing a small and brief suffering to a few animals as the price of the salvation of his fellow-creatures from the far greater pain which is the assured and fatal companion of ignorance--accursed ignorance!