Timeline created by cawker
  • Jean-Baptiste von Helmont 1577 - 1644

    placed wheat grain in a sweaty shirt. After 21 days the wheat was gone but mice were present. He suggested that an active principle (sweat) changed the wheat into mice. No controls on the experiment
  • Francesco Redi supported biogenesis

    placed meat in open containers. maggots appeared. Studied the maggots. Placed some meat in open jars and some in sealed jars, and some in jars with cloth coverings. Observed no maggots in sealed jars nor cloth covered jars. He suggested maggots come from other flies not from meat.
  • John Needham 1713-1781

    boiled flasks of chicken, pork and corn. sealed the containers. After several days he opened the flasks and found them full of microorganisms.