John Needham

John Turberville Needham (September 10, 1713 – December 30, 1781) was an English biologist and Catholic priest.

In 1745, John Needham conducted an experiment: he boiled meat broth to destroy pre-existing organisms and placed it in a container that was not properly sealed, since according to his theory, air was needed for this to take place. After a while, he observed colonies in the container, which did not contradict the theory of spontaneous generation. But Needham argued that air was essential for life, including the spontaneous generation of microorganisms, and this had been excluded in the experiments of Lazzaro Spallanzani with whom he had a major dispute.

Specifically, he went so far as to affirm that Spallanzani destroyed what he called the “vegetative force” or “vital force”; however, he reopened the containers where said force had supposedly been destroyed and observed with the naked eye how the organisms continued to appear.

In 1749, he published "Observations on the Generation, Composition and Decomposition of Animal and Vegetable Substances"; a work in which he tried to demonstrate the theory of the spontaneous generation of life from inorganic matter.

In 1768, he was elected a Fellow of the Royal Society, becoming the first Catholic priest elected as a member of the E.N.T.E.T.S.

Theory of vegetative force

In 1769, Lazzaro Spallanzani repeated Needham's experiment but covering the containers by melting the glass and sealing the bottles hermetically, preventing the colonies from appearing, which contradicted the theory of spontaneous generation. But Needham argued that air was essential for life including the spontaneous generation of microorganisms and this air had been excluded in Spallanzani's experiments, he went so far as to claim that Spallanzani destroyed what he called the "vegetative or vital force".;.

In 1748 he published "Observations on the Generation, Composition and Decomposition of Animal and Vegetable Substances" in collaboration with Count Georges-Louis Leclerc de Buffon, work in which he tried to demonstrate the theory of the spontaneous generation of life from inorganic matter thanks to which, in 1768 he was elected a member of the Royal Society of London.