The_Invention_of_Surgery

microscope. Koch was the unwitting exemplar of laboratory animal
experimentation: his use of rabbits and mice (including his own breeding
program of white mice) continues in every university setting in the world,
gaining its start in tiny Wöllstein.
Koch experimented further, attempting to culture the anthrax bacteria
outside a living host. Undoubtedly, the pioneer was confused about the
waves of anthrax plagues that had always occurred. What was the secret of
the organism’s ability to rapidly propagate after months (or years) of
quiescence? Robert Koch was now sailing into uncharted waters. The few
visionary scientists who suspected the villainy of the innocuous-appearing
germs that existed at the other end of the metal tube of their microscopes
had never succeeded in incubating germs.
Convinced that the bacteria were living organisms that needed
sustenance, Koch tinkered with body fluids that could provide a growth
medium. In a macabre solution, he used the aqueous humor, the fluid
contained within eyeballs (procuring them from slaughterhouse cattle).
Koch used his dissection tools to gather a small sample of infected mouse
spleen, mixing it into the aqueous humor on a thin glass slide. He mated
that slide against a stouter glass slide that had a small concavity he had
created. The fluid mixture was held in place by a small ring of petroleum
jelly, creating a sealed culture environment.
Koch placed his contrivance on his Zeiss microscope stage and tuning
the large brass knurled focusing ring, peered into the fluid, finding
nothing. He scrupulously scanned the slide, but couldn’t find any bacteria.
He set his microscope aside for an hour, anxiously returning to see if any
growth had occurred, but still found no change. Two hours later, Koch
inspected, but was again disappointed. Then, after a few hours, Koch saw
something wonderful: whorled stacks of rice-shaped rods started to appear.
In time, the entire world underneath his own eyeball was replete with the
anthrax bacteria, which Koch would call Bacillus anthracis.
The anthrax colonies started revealing different shapes as they matured.
Koch observed that the long rods enlarged in time, and then birthed small
round spores, which recently had been reported by Ferdinand Cohn, of the
University of Breslau (now Wroclaw, Poland). Koch’s breakthrough began
with subsequent experiments, where he began altering conditions. He had
found success with aqueous humor, but now Koch (accidentally?)
considered the effects of drying or heating cultured samples. He grew