The term "Contagium vivum fluidum" (meaning "contagious living fluid") was proposed by M. W. Beijerinck. He coined this phrase in 1898 to describe the agent responsible for tobacco mosaic disease, which he found could pass through filters, distinguishing it from bacteria.

M.W. Beijerinck (Martinus Willem Beijerinck) is credited with this concept based on his experiments with tobacco mosaic virus.

D.J. Ivanowski (Dmitri Ivanovsky) is known for discovering that the causative agent of tobacco mosaic disease could pass through porcelain filters (filterability) in 1892, but he did not propose the "contagium vivum fluidum" phrase.

W.M. Stanley is noted for crystallizing the tobacco mosaic virus.

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