442 
CONGRESS ON TUBERCULOSIS. 
from the first, and so will everybody have been who had con¬ 
vinced himself of the causal relation between tuberculosis and the 
tubercle-bacillus. But the strength of a small number of med¬ 
ical men was inadequate to the conflict with a disease so deeply- 
rooted in our habits and customs. Such a conflict requires the 
cooperation of many, if possible of all, medical men, shoulder to 
shoulder with the state and the whole population ; but now the 
moment when such cooperation is possible seems to have come. 
I suppose there is hardly any medical man now who denies the 
parasitic nature of tuberculosis, and among the non-medical 
public too the knowledge of the nature of the disease has been 
widely propagated. 
Another favorable circumstance is that success has recently 
been achieved in the combating of several parasitic diseases, 
and that we have learned from these examples how the conflict 
with pestilences is to be carried on. 
The most important lesson we have learned from the sad 
experience is that it is a great blunder to treat pestilences uni¬ 
formly. This was done in former times ; no matter whether 
the pestilence in question was cholera, plague, or leprosy : iso¬ 
lation, quarantine, useless disinfection were always resorted to. 
But now we know that every disease must be treated according 
to its own special individuality, and that the measures to be 
taken against it must be most accurately adapted to its special 
nature, to its etiology. We are entitled to hope for success in 
combating tuberculosis only if we keep this lesson constantly 
in view. As so extremely much depends just on this point. I 
shall take the liberty to illustrate it by several examples. 
The pestilence which is at this moment in the foreground of 
interest, the bubonic plague, may be instructive to us in several 
respects. 
People used to act upon the conviction that a plague patient 
was in the highest degree a centre of infection, and that the dis¬ 
ease was transmitted only by plague patients and their belong¬ 
ings. Even the most recent international agreements are based 
on this conviction. Although, as compared with formerly, we 
now have the great advantage that we can, with the aid of the 
microscope and of experiments on animals, recognize every case 
of plague with absolute certainty, and although the prescribed 
inspection of ships, quarantine, the isolation of patients, the dis¬ 
infection of infected dwellings and ships, are carried out with 
the utmost care, the plague has, nevertheless, been transmitted 
everywhere, and has in not a few places assumed grave dimen- 
