Of all diseases based on tuberculosis only ringworm or lupus is perceivable by the eye, as it is a disease of the skin, all other tuberculous diseases take their course in the internal parts of the body, and therefore are not perceptible to the eye. The symptoms that follow an injection of Koch's liquid can be best observed in the case of lupus.
Koch therefore selected for his first illustration patients afflicted with lupus that is ringworm. Even a few hours after the injection the first perceptible changes begin to show in the diseased parts. These begin to swell and redden; in other words an inflammation is caused, through which the diseased tissue is obviously brought to mortification. Soon the inflammation stops. The gangrenous tissue changes into crusts or scabs which drop off in a short time and the patient is cured of his ringworm.
Koch places particular importance on the fact that the inflammation is restricted to the diseased parts only, and that it does not attack sound and healthy parts. Even the smallest otherwise invisible knots are made perceptible through the inflammation.
We have similar illustrations for this specific action of Koch's remedy for lupus (ringworm). So for instance a syphilitic ulcer on the thigh may be cured in a few days with iodide of potassium. In a similar manner a morbidly enlarged spleen may be reduced to the normal size by taking quinine.
The observation is very interesting indeed, as it may be shown whether a person is tuberculous in any organ or not by the injection of .01 ccm. In case he is tuberculous the poisoning symptoms appear in a marked degree; if he is not, hardly any effect is noticeable.
Although we have had excellent methods for a long time to detect pulmonary consumption, although Koch added the discovery of the tubercle bacilli, it occasionally happens that the disease can not be recognized in its beginning stages, because its progress is too slight. Now the reaction following an injection is to be the deciding medium. Also with other tuberculous affections physicians will welcome this diagnostic auxiliary, for in the beginning of the same it often happens that no certain diagnosis could be made and valuable time was lost.
We must call particular attention to the further statements of Koch, that through his remedy the tubercle bacilli are not killed. With this it is admitted that the remedy will not be able to effect cures, without any more ado, yes, even the tubercle bacilli may continue to infect parts of the body even in spite of the action of the remedy.
Therefore the application of Koch's remedy only, is not sufficient to effect a cure. Provision must be made to remove the gangrenous tissue from the body as rapidly as possible, because it contains the still living tubercle bacilli. As a rule surgical aid is necessary to remove the mortified tissue. Where this is impossible Koch advises the continued application of the remedy to protect the endangered living tissue from the re-immigration of the tubercle bacilli. Koch thereby believes that he can protect the tissue, perhaps in the manner as vaccination protects from small pox.
The rapid increase in the quantity of the remedy applied in the course of time is something that has no parallel. Koch gives an explanation, but leaves it to the future to be confirmed. We have no previous instance in case that his explanation should prove correct. Reasoning from analogous application of our remedy, we are led to assume that smaller quantities of the substance would suffice to cause mortification of the remaining tuberculous tissue. Koch on the other hand uses larger and larger doses to reach a result. He admits inurement to the remedy within certain limits only.
Koch has made a difference between pulmonary consumptives and those suffering from tuberculosis of the bones and joints, etc. He was able to inject larger quantities in the latter than the former, for the quantity injected in the case of pulmonary consumptives was .001 ccm.; in other tuberculous cases .01 ccm.