744 Tuberculosis 



Experiment showed that TR had decided immunizing 

 powers. Injected into tuberculous animals in too large a dose 

 it produces a reaction, but its immunizing effects were entirely 

 independent of the reaction. Koch's aim in using this 

 preparation in the therapeutic treatment of tuberculosis was 

 to produce immunity against the tubercle bacillus without 

 reactions by gradual but rapid increase of the dose. In so 

 large a number of cases did Koch produce immunity to 

 tuberculosis by the administration of TR, that he believes 

 it proved beyond a doubt that his observations are correct. 



By proper administration of the TR he was able to render 

 guinea-pigs so completely immune that they were able 

 to withstand inoculation with virulent bacilli. The point 

 of inoculation presents no change when the remedy is ad- 

 ministered; and the neighboring lymph-glands are generally 

 normal, or when slightly swollen contain no bacilli. 



In speaking of his experiments upon guinea-pigs, Koch 

 says: 



"I have, in general, got the impression in these experiments that full 

 immunization sets in two or three weeks after the use of large doses. A 

 cure in tuberculous guinea-pigs, animals in which the disease runs, as is 

 well known, a very rapid course, may, therefore, take place only when 

 the treatment is introduced early as early as one or two weeks after the 

 infection with tuberculosis. 



''This rule avails also for tuberculous human beings, whose treat- 

 ment must not be begun too late. ... A patient who has but a few 

 months to live cannot expect any value from the use of the remedy, and 

 it will be of little use to treat patients who suffer chiefly from secondary 

 infection, especially with the streptococcus, and in whom the septic 

 process has put the tuberculosis entirely in the background." 



One very serious objection, first urged against commer- 

 cially prepared TR by Trudeau and Baldwin,* is that it is 

 possible for it to contain unpulverized, and hence still living, 

 virulent tubercle bacilli. Thellingf could not observe any 

 good effect to result from the use of Koch's new tuberculin, 

 and, like Trudeau, found living, virulent bacilli in the prepa- 

 ration secured from Hochst. Many others have since dis- 

 covered the same danger. In the preparation of the remedy 

 it will be remembered that no antiseptic or germicide was 

 added to the solutions by which the effects of accidental fail- 

 ure to crush every bacillus could be overcome, Koch having 

 specially deprecated such additions as producing destruc- 

 tive changes in the TR. Until this possibility of danger can 

 be removed, and our confidence that attempts to cure 



* "Medical News," Aug. 28, 1897. 



t "Centralbl. f. Bakt.," etc., July 5, 1902, xxxn, No. i, p. 28. 



