It is thus seen that methods of biological research which involve cruel or destructive experimentation are both ethically unjustifiable and intellectually fallacious. They are unscientific methods which will inevitably be abandoned as we attain to clearer views of that unity of truth in which the reconciliation of human conscience with intellectual activity becomes alone recognised as science.
CHAPTER X
Rational Experiment in Research
As an illustration of legitimate and even heroic experiment, the trial made with cholera bacilli by Dr. Von Pettenkofer of Munich on himself during the cholera epidemic of 1891 deserves permanent record.[19] It is of importance as showing the fallacy that may be involved in the exaggerated search for bacilli, as the chief cause of disease, which is the favourite theory and practice of the present day.
Dr. Von Pettenkofer (in opposition to the common medical belief) asserts that the diffusion of the cholera germ or cholera bacillus is not the chief cause of cholera. He states that there are two other absolutely necessary conditions, without which no outbreak of cholera is possible, and if these conditions are not present, the cholera germ may be breathed with no production of cholera.
The first condition is the unhealthy state of the soil or locality. But even this does not produce an outbreak if the second condition does not exist—viz., individual predisposition; and he shows that neither the cholera germ nor the insanitary locality, nor both combined, will produce cholera if this individual predisposition does not exist. He further states that no experiments upon the lower animals can be relied on; the only proof in relation to cholera must be from the experience of human beings.
Dr. Von Pettenkofer proceeded to experiment on himself, choosing Munich, in daily communion with Hamburg (where the epidemic was raging), as the place of operations, and sent to Hamburg for the cholera germs. On October 7 he swallowed a centimetre of fresh cholera culture, in the presence of witnesses—i.e., infinitely more than could be taken in by touching the lips with contaminated fingers, a cubic centimetre of culture being calculated as containing a thousand million microbes. He in no way changed his manner of living, eating accustomed food, including fruit, cucumbers, and other forbidden articles of diet. During the following week his physiological condition, pulse, temperature, etc., were carefully noted. Nothing unusual occurred but a little internal rumbling and slight diarrhœa, which passed away of itself. Two skilled bacteriologists, MM. Peiffer and Emerich, carefully examined the secretions during this experiment.
M. Von Pettenkofer himself thus states the results:
‘The comma bacilli not only prospered in my digestive tube, but had so multiplied in it that it was evident they found a congenial soil. They were found there in quantities, and in a state of pure culture. But on October 14 all the secretions were normal, only containing a few isolated microbes, which had entirely disappeared on the 18th.
‘Now, most bacteriologists assert that the cholera bacilli remaining in the intestines secrete there a poison, which, being absorbed, produces the cholera. But what a quantity of poison must have been secreted by these milliards of bacilli during the eight days’ sojourn in my intestines! Yet I felt perfectly well, had an excellent appetite, felt neither indigestion nor fever, etc., and I attended every day to my usual occupations. Whence I conclude that the comma bacillus, though it may cause a little diarrhœa, produces neither European nor Asiatic cholera.
‘Now, it must not be imagined that I am the adversary of the cholera bacillus; but it is erroneous to suppose that when a specific microbe has been discovered in the secretions of an infectious disease that the means of fighting it has also been discovered. The discovery of the bacillus of consumption was just as interesting as the discovery of the cholera bacillus, but since its discovery phthisis has destroyed neither one man less nor one man more.