resort. When it shall have done this it will have
fulfilled its mission.

Our plan of campaign is growing broader and more ambitious, but more
hopeful, every day. All we have to do is to keep on fighting and use our
brains, and victory is certain. Our Teutonic fellow soldiers have
already nailed their flag to the mast with the inscription:--

"No more tuberculosis after 1930!"

So much for the serried masses of the centre of our anti-tuberculosis
army, upon which we depend for the heavy, mass fighting and the great
frontal attacks. But what of the right and the left wings, and the cloud
of skirmishers and cavalry which is continually feeling the enemy's
position and cutting off his outposts? Upon the right stretch the
intrenchments of the bacteriologic brigade, with the complicated but
marvelously effective weapons of precision given us by the discovery of
the definite and living cause of the disease, the _Bacillus
tuberculosis_. Upon the left wing lie camp after camp of native
regiments, whose loyalty until of very recent years was more than
doubtful,--heredity, acquired immunity, and the so-called improvements
of modern civilization, steam, electricity, and their kinsmen.

To the artillerymen of the bacteriologic batteries appears to have been
intrusted the most hopeless task, the forlorn hope,--the total
extermination of a foe so tiny that he had to be magnified five hundred
times before he was even visible, and of such countless myriads that he
was at least a billion times as numerous as the human race. But here
again, as in the centre of the battle-line, when we once made up our
minds to fight, we were not long in discovering points of attack and
weapons to assault him with.

First, and most fundamental of all, came the consoling discovery that
though there could be no consumption without the bacillus, not more than
one individual in seven, of fair or average health, who was exposed to
its attack in the form of a definite infection, succumbed to it; and
that, as strongly suggested by the post-mortem findings already
described, even those who developed a serious or fatal form of the
disease had thrown off from five to fifteen previous milder or slighter
infections. So that, to put it roughly, all that would be necessary
practically to neutralize the injuriousness of the bacillus would be to
prevent about one-twentieth of the exposures to its invasion which
actually occurred. The other nineteen-twentieths would