• Hans and Zacharias Janssen

    Hans and Zacharias Janssen
    The Janssens were the first people ever to create a microscope. It was a thin, long tube that looked like a telescope. The Janssens were spectacle makers, so it makes sense why they would make the first microscope. They just started experimenting by putting several lenses in a tube, and then “BAM!” They could see really small things or really far away.
  • Robert Hooke

    Robert Hooke
    Robert Hooke, in 1663, looked at cork under a microscope and observed that, "These pores, or cells, were not very deep, but consisted of a great many boxes." He concluded that since the cork came from a tree, a living thing, it still had cells, even if dead.
  • Francesco Redi

    Francesco Redi
    Francesco Redi placed meat in two jars, one without a lid and one with a cloth that lets air into the jar. Later, he saw maggots on the meat in the open jar, but there were no maggots on the meat in the covered jar. Redi proved that flies had laid eggs on the meat in the open jar, but the flies couldn't lay eggs on the covered jar because of the cloth. He concluded that meat cannot produce maggots.
  • Spontaneous Generation

    Spontaneous Generation
    Spontaneous generation was the idea that living things, like bacteria or maggots, could arise from nonliving things, such as meat or broth. This idea was proven wrong after Pasteur & Redi’s experiments.
  • Terrain theory

    Terrain theory
    The terrain theory states that weakened or poorly defended skin or tissue will attract germs acting as scavengers.
  • Antonie Van Leeuwenhoek

    Antonie Van Leeuwenhoek
    In 1680, Antonie Van Leeuwenhoek discovered protozoa, which are single celled organisms like bacteria. He called them “animalcules”. He is sometimes known as the first person to study muscle fibers, but that is not proven.
  • Lazarro Spallanzani

    Lazarro Spallanzani
    Spallanzani conducted an experiment very similar to that of Louis Pasteur. He put broth into 4 flasks, one unboiled and uncorked, one unboiled and corked, one boiled and uncorked, and the last one boiled and corked. Microbes were found in the first 3 flasks, but not in the last one. He therefore concluded that bacteria can only grow from other bacteria.
  • Matthias Schleiden

    Matthias Schleiden
    Schleiden looked at vegetables under a microscope and saw the same thing that Robert Hooke saw in the piece of cork. Many little boxes. He then concluded basically everyone else who is doing this type of experiment and getting the same results is correct.
  • Theodor Schwann

    Theodor Schwann
    Schwann declared that all animals and plants are made of cells. It took him looking at other scientist’s experiments as well as his own to make this conclusion.
  • Rudolf Virchow

    Rudolf Virchow
    Virchow was also someone that concluded that all cells have to come from other living cells. Except he looked at other things, like bone and tissue. Virchow was the very first person to see and recognize leukemia.
  • Louis Pasteur

    Louis Pasteur
    Pasteur put the same broth into two of the same flasks and boiled one flask. The other broth remained unboiled. After a few days the boiled broth was still clear, but the unboiled broth was cloudy.
  • Germ Theory

    Germ Theory
    The germ theory is the theory that specific diseases can be caused by bacteria or protazoa entering the body.
  • Robert Koch

    Robert Koch
    Koch is known by many as the founder of bacteriology. His work was a HUGE contribution to the development of ‘magic bullets’, which are chemicals designed to attack certain types of bacteria.
  • Antoine Béchamp

    Antoine Béchamp
    Béchamp proposed a theory almost opposite of that of Louis Pasteur. Béchamp’s stated that the same bacteria that grew in Pasteur’s broth is everywhere. Béchamp’s theory said that only when a tissue of the person was damaged then did the bacteria get in.
  • Sources
    Science Textbook