has himself left a record in strong English of the way he felt. Writing to Moore in 1811 he says: "The town is a fool, an idiot, and will continue in this red-hot, hissing-hot state about this affair until something else starts up to draw aside its attention. I am determined to lock up my brains and think no more pro bono publico, and I advise you, my friend, to do the same, for we are sure to get nothing but abuse for it."[1]
We are, however, discussing the utility of a method, and while we will not introduce Koch's treatment as an argument for the utility of vivisection until it has been perfected and the medical profession has reached a decision as to its value, we can hardly find a better example of the vivisectional method. Koch's method is that of Jenner perfected by using animals instead of men. His discovery in 1883 of the tubercle bacillus has already become of inestimable value in directing sanitary measures and in recognizing the earlier stages of consumption while cure is possible. This, we are told by an antivivisection writer, "was discovered by the microscope, not by vivisection."[2] How did Koch make this discovery?
It is true the microscope assisted as spectacles help to read. But Koch, in the examination of tuberculous matter, discovered a number of germs with the microscope. Which one of these caused consumption no number of microscopes could tell him. This had to be settled by most careful experiments. There are several steps in the process. The first is to identify all the different kinds of microbes found constantly in tuberculous bodies. For convenience we will call these microbes a, b, c, d. These are mingled together. The second step is to cultivate these germs in one test tube after another until perfectly "pure cultures" are obtained—i. e., nothing but a's in one, nothing but b's in another, and so on. Up to this stage he has not the least idea which of these is the germ of consumption. The only way he can determine this point is by experimenting upon living animals. He must then inoculate a number of healthy animals, one with germ a, another with germ b, another with germ c, another with germ d. The four animals are now watched carefully. The animal inoculated with germ a, we will say, sickens and dies with unmistakable symptoms of tuberculosis. Those inoculated with germs b, c, and d are not affected. He repeats the experiment several times, and if each time with the same result is justified in concluding that germ a is the cause of tuberculosis, while the other germs are harmless.
This is but the first stage in the investigation. After the dis-
