, the bacterium of cholera. Here, again he
had the enemy at bay. For long ages the Asiatic plague had ravaged the
countries of the East with little hindrance to its spread or fatality.
The disease would appear as an epidemic at intervals and sweep all
before it. The wave of death would roll on westward from country to
country, until it would subside, as if by exhaustion, in the far west.
Two or three times within the century cholera had been fatally
scattered through American cities. It had spread westward along the
rivers of the Ohio and Mississippi valleys, and into country
districts, where villages and hamlets were decimated.

The discovery of Koch was a virtual proclamation that this ruin of
mankind from the Asiatic plague should cease. The knowledge that the
disease was due to a living bacterium, that without the germ and the
spread of the germ the plague could not exist, was a virtual
announcement that in the civilized countries it should _not_ any
longer exist.

The discoverer was now set high in the estimation of mankind. Imperial
Germany best of all countries rewards its benefactors. France is
fascinated with adventure; Great Britain with slaughter; America with
bare political battles; but Germany sees the true thing, and rewards
it. Koch was immediately placed beyond want by his government, and
titles and honors came without stint.

The Empire would fain have such a man at the seat of power. Dr. Koch
was, in 1885, made a professor in the University of Berlin. The new
chair of Hygiene was created for him, and he was made Director of the
Hygienic Institute. It was in this capacity that armed with influence
and authority and having the resources of the government virtually at
his disposal, he directed in the great scientific work by which a
bulwark against cholera was drawn almost literally across Europe, and
was defended as if with the mounted soldiery of science and humanity.
True enough, cholera managed to plant itself in Italy in 1886, and in
Hamburg in 1892, and the plague was scattered into several German
towns. But it came to Hamburg by water, not by land. It did there
during the summer a dreadful work, but the battle was the Waterloo of
the enemy. Not again while the present order continues will it be
possible for the dreaded epidemic to get the mastery of a great German
city.

It was to be anticipated that Dr. Koch's discovery of the tubercle
bacillus would lead him on to the discovery of a cure for