number of victims which would have suffered if the few had not been sacrificed. Can it be wondered at that medical men, whose experience is so different to theirs, feel otherwise? The doctor's life is not one in which these are just a few painful partings with dear ones, but he is steeped in such experiences from morning till night. His sympathies aim at the relief and cure of all this evil; and the death of a few guinea-pigs or rabbits is a necessary incident which he has the courage to permit because of the greater good that is the ultimate result.

There are, however, some of the examples which ought to stir better feelings even in the Anti-vivisectionist camp, namely, cases of diseases which are common or used to be common in our very midst, and which we need not go to India or Malta to look for. One of these is diphtheria, and the statements and statistics in relation to the almost miraculous change which has come over our ideas on this affection are incontrovertible, and are fully set forth in the following pages. The disease no longer inspires the terror it used to do, for it is one which can be cured, and easily cured, by the method of serum therapy. It has not, it is true, been stamped out, for up till the present success has not attended efforts of prevention. Prevention is better than cure, but cure is better than suffering and death. Just now, medical science can cure the disease, and if medical progress continues at its present rapid rate of growth, who can doubt that in the near future this disease, like typhus and typhoid, will be stamped out?

Typhoid fever is an example of a disease which has only died out in this country quite recently. When I was a student the hospital wards were full of it; but to-day most medical students in London pass through their entire curriculum of five years or more without ever seeing a case. What has been accomplished for London can also be carried out in other large cities, and the extinction of the disease is entirely due to improved sanitary measures, and the destruction of the bacillus which causes the malady. We often quite legitimately complain of the extravagances of our Government departments and our County Councils, and of their apathy in questions affecting the health of the country. We are still awaiting, for instance, proper legislative measures to ensure the purity of milk. But this at least we can thank them for—proper methods of disinfection and a purer water-supply have led to the almost complete extinction of what was a common and painful and fatal disease. But how does Vivisection come in here? County councillors are not Vivisectors. No, they are not, but their action is the undoubted result of public opinion; and that healthy public opinion is the outcome of medical opinion, which was preached to deaf ears for many years, and at last succeeded in impressing itself upon the public at large; and this medical knowledge was the offspring of the only certain guide in such matters, pathological experiment. It was not until the germ of typhoid fever was recognised and isolated, not until the conditions of its growth and the means of its destruction were experimentally verified upon the lower animals, that any sound knowledge was obtained. Bacteriology is at the bottom of hygiene; it is by hygienic precautions that certain diseases are prevented; and the basis of bacteriology is experiment on animals.

I will allow myself only one more point, and that relates to the general question of serum therapy. Some people object to the whole conception of serum treatment, on the ground that serum and allied substances are 'messy' things. It was by this very expressive phrase that Lord Justice Fletcher Moulton summarised and paraphrased the Anti-vivisectionist attitude on the serum method of treatment. Miss Lind af Hageby on one occasion characterised it as 'medieval,' a word which is quite meaningless in this connection, but prettier, I admit, than "Behring's filth product," which is the elegant name coined for antidiphtheritic serum by one of her friends.

Filth or dirt has been well defined as matter in the wrong place. Blood on a carpet, for example, is certainly messy and dirty; it ought not to be there. But blood or serum (the fluid part of the blood) in the heart, or in the arteries and veins, is in its rightful place, and it does its duty of nutrition and so forth when it comes into more immediate contact with the tissues in the small tubes we call the capillaries. One of these duties is to exert a protective influence upon the whole body, by destroying the germs of disease which get in, despite all precautions. We are all of us exposed, so long as spitting in public places is not prohibited, to the germs of consumption, but we do not all die of that disease. This is because the white corpuscles of our blood are in good trim, and able successfully to devour the bacteria that enter our interior. It is those people who are run down, and in whom the white corpuscles are 'below par,' that catch the disease. In assisting the white corpuscles to perform this important function, the co-operation of certain substances dissolved in the fluid portion of the blood is also necessary. The most recently discovered of these auxiliary substances are called opsonins. The word opsonin is derived from a Greek root which means "to prepare the feast." The opsonin either adds something to the bacterium which makes it tasty to the white corpuscle, or removes (or neutralises) something which previously made it distasteful. White corpuscles will not as a rule ingest and devour bacteria from a pure culture, but they do so eagerly immediately the bacteria are bathed in serum; and the serum which is most efficacious in acting as a sort of sauce is that which has been obtained from an animal which has been previously infected with the same kind of bacteria, and which has recovered from the ailment such bacteria have set up.

This is not mere fancy: the whole sequence of events can be easily followed on a glass slide kept at body temperature and examined with a microscope.

It is well known that if the yeast plant (which is very similar in many details to bacteria) is grown in a solution of sugar, the sugar is broken up and disappears, and two new substances formed from the sugar take its place. These are alcohol and carbonic acid gas. If bacteria grow in the blood, they do not produce alcohol, but they do produce other poisons in a way analogous to that by which yeast produces alcohol. These poisons are called toxins. There are substances in the fluid part of the blood which are called antitoxins, because they neutralise the toxins produced by the bacteria. Their presence constitutes a means of defence against the harmful effects the toxins would otherwise produce. The marvellous part of the defence is that, although we all have a certain amount of antitoxin in our blood, the amount increases in proportion to the amount of toxin. It is a familiar fact that rough manual labour increases the hardness of the hands; friction stimulates the epidermis or outer skin, so that it grows in thickness. The body affords numerous similar instances of how it is capable of rising to the occasion and increasing its defences. Just in the same way, the presence of a toxin stimulates the living cells to produce more and more antitoxin, and the blood remains rich in the antitoxin for a considerable time afterwards. This explains why a person who has had an infectious disease does not take it readily a second time; he is immune for a certain number of years, because his blood is so rich in the antidote.

Now, the principle of serum