The slow death of spontaneous generation

Francesco redi

1626

Francesco Redi (1626-1697) was an Italian physician, poet and naturalist known for his work in refuting the theory of spontaneous generation and for his studies on insects and poisons. He conducted an experiment to disprove the theory of spontaneous generation.

Francesco redi

1626

Francesco Redi (1626-1697) was an Italian physician, poet and naturalist known for his work in refuting the theory of spontaneous generation and for his studies on insects and poisons. He conducted an experiment to disprove the theory of spontaneous generation.

redi's experiment

1668

Francesco Redi was the first to disprove spontaneous generation but not quite, he began to spread his idea using an experiment consisting of 3 jars of meat: one was completely closed, one was covered with a cloth and the last one was left in the open air.
His hypothesis was that organisms that seemed to arise spontaneously did not form where they appeared. He concluded that maggots could only hatch in the meat when flies had access to it or on top of the cloth.

John Needham

Oct 9, 1713

John Needham (1713-1781) was an English naturalist and Catholic clergyman known for his contributions to the theory of spontaneous generation and microbiology.
He tried to prove that spontaneous generation was a true theory and, for a time, succeeded.

Lazzaro Spallanzani

Dec 1, 1729

Lazzaro Spallanzani (1729-1799) was an Italian naturalist, biologist and physiologist known for his contributions to biology, especially in the fields of animal physiology and reproduction. He did a lot of experiment one of which was an experiment to disprove Needham's theory.

Needham’s experiment

1738

John Needham created a refutation of Redi's results.
Needham did an experiment in which the sauce was boiled to be sterilised. The experiment consisted of taking two glass jars of sauce and closing them hermetically and, a couple of days later, he observed that microbes such as moulds grew in the sauce, proving that life came from non-living matter such as the sauce.

Lazzaro Spallanzani experiment

1768

Spallanzani's experiment consisted of heating meat broth in a jar and sealing it hermetically. He then placed it in a boiling water bath for an hour to kill any organisms present. Once the jar cooled, he let it sit in a dark place and observed that no microscopic life was produced in the broth.
He also did the same experiment but with a glass jar with a long, curved neck, he demonstrated that organisms did not arise spontaneously from inert matter, but came from other already existing organisms.

Louis Pasteur

1822

Louis Pasteur (1822-1895) was a French microbiologist and chemist who made important contributions to medicine, chemistry and biology.

Louis Pasteur experiment

1862

Pasteur demonstrated the non-existence of spontaneous generation by recreating the experiment but leaving room for air to enter the broth. The broth remained free of micro-organisms as long as the neck of the flask remained intact and unopened. However, when the neck of the flask was broken, micro-organisms started to appear in the broth. This showed that micro-organisms do not appear spontaneously, but come from the air.