Spontaneous generation was a (refuted) theory that some forms of life can arise from inorganic matter.
Louis Pasteur refuted it in a series of experiments, in which he boiled different matter (grape juice, broth) which would kill all the bacteria and let it stay for a long time to see if it would develop life (he also had a control condition in which he let the boiled liquid interact with the outside words, and those would develop bacterial life).
