in Germany.

Had space allowed, it would have given me pleasure to point out the
present position of the 'germ theory' in reference to the phenomena of
infectious disease, distinguishing arguments based on analogy--which,
however, are terribly strong--from those based on actual observation.
I should have liked to follow up the account I have already given
[Footnote: 'Fortnightly Review,' November 1876, see article
'Fermentation.'] of the truly excellent researches of a young and an
unknown German physician named Koch, on splenic fever, by an account
of what Pasteur has recently done with reference to the same subject.
Here we have before us a living _contagium_ of the most deadly power,
which we can follow from the beginning to the end of its life cycle.
[Footnote: Dallinger and Drysdale had previously shown what skill and
patience can accomplish, by their admirable observations on the life
history of the monads.] We find it in the blood or spleen of a
smitten animal in the state say of short motionless rods. When these
rods are placed in a nutritive liquid on the warm stage of the
microscope, we soon see them lengthening into filaments which lie, in
some cases, side by side, forming in others graceful loops, or
becoming coiled into knots of a complexity not to be unravelled. We
finally see those filaments resolving themselves into innumerable
spores, each with death potentially housed within it, yet not to be
distinguished microscopically from the harmless germs of Bacillus
subtilis. The bacterium of splenic fever is called Bacillus
Anthracis. This formidable organism was shown to me by M. Pasteur in
Paris last July. His recent investigations regarding the part it
plays pathologically certainly rank amongst the most remarkable
labours of that remarkable man. Observer after observer had strayed
and fallen in this land of pitfalls, a multitude of opposing
conclusions and mutually destructive theories being the result. In
association with a younger physiological colleague, M. Joubert,
Pasteur struck in amidst the chaos, and soon reduced it to harmony.
They proved, among other things, that in cases where previous
observers in France had supposed themselves to be dealing solely with
splenic fever, another equally virulent factor was simultaneously
active. Splenic fever was often overmastered by septicaemia, and
results due solely to the latter had been frequently made the ground
of pathological inferences regardi