What Was John Needham’s Experiment?

John Needham’s experiment involved placing a broth into a bottle, heating it and then sealing it. Days later, Needham found the presence of life, and eventually announced that life had been created from nonliving material. This supported the incorrect idea that life could come from nonliving things.

Needham believed that his heating of the broth was sufficient to kill all living things. His subsequent observation of life in the broth led to his conclusion that living things could arise from nonliving material.

A subsequent scientist, Lazzaro Spallanzani, was able to refute Needham’s theory through experiments by properly heating broth, and then comparing sealed broth with unsealed broth. However, Spallanzani’s experiments were inconclusive to some, because it was argued that Spallanzani’s methods deprived air from the mixture, which may have been the critical ingredient for life to come from nonliving things. Louis Pasteur eventually resolved the issue by allowing air, and only air, to come in contact with properly heated broths and showing that no life resulted from the nonliving material.

Prior to Pasteur’s experiments that proved that life could not come from nonliving things, it was believed by many that life could arise spontaneously. Examples of this incorrect understanding included flies from manure, maggots from meat and fish from the mud of dry lakes. During the late 1600s and 1700s, a series of experiments were performed by multiple scientists that attempted to prove conclusively if life could arise form nonliving things.