Tools That Louis Pasteur Used

Louis Pasteur is widely remembered for discovering the process that now bears his name, pasteurization, which keeps milk, wine and beer from souring. But that was just one among many notable achievements. When he died aged 73 in 1895, he was a national hero in his native France for his discoveries in microbiology, immunology and vaccination.

Vaccines

• In particular, Pasteur proved germ theory to be true, proved the widely held belief in spontaneous generation of life to be untrue, saved the French silk industry from ruin by curing two silkworm diseases, and found vaccines for anthrax, chicken cholera, and rabies.

Microscope

• As a chemist he used many tools, most of them the standard laboratory equipment of his generation, but one in particular -- the microscope -- was critically important to his successes. The concept of germs causing infection was just a theory until Pasteur proved its truth.

  In one controversy his opponent "didn't even bother looking through a microscope," while Pasteur employed a variety of tools to make his case, particularly the microscope. His recommendation that hospitals boil surgical tools was ignored until the 20th century.

Quality Control

• He taught breweries how to use the microscope for quality control. While studying fermentation, he saw under the microscope that properly aged wine contains small spherical globules of yeast cells whereas sour wine contains elongated yeast cells. This was the beginning of the process that led to pasteurization. Pasteur showed keen awareness of the importance of his tools when he commented: "A science is as mature as its measurement tools."

'Spontaneous life'

• Bowls of broth became his most unusual "tool." Arguments had been going on since classical times as to whether life could be spontaneously generated. By 1860, the debate was heated and the French Academy offered a cash prize to anyone who could resolve it one way or the other. Pasteur did, but it took four years.

  He created a series of closely-controlled experiments using bowls of broth and three different kinds of flasks -- straight neck, swan neck with liquid in the U-bend, and sealed. "Life," in the form of microorganisms, only appeared in the open flasks. Air containing dust could not enter the other types. Pasteur demonstrated that spores in the air, invisible to the naked eye, accounted for the "life" in the open-flask broth.

Pasteur Pipette

• A tool has been named after him -- the "Pasteur pipette," a small tube with a hollow rubber bulb at one end, more commonly known now as an eyedropper. Pasteur created his own version in order to transfer small amounts of liquid in a controlled way.