Antoine Béchamp

French scientist now best known for breakthroughs in applied organic chemistry and for a bitter rivalry with Louis Pasteur.

Béchamp developed the Béchamp reduction, an inexpensive method to produce aniline dye, permitting William Henry Perkin to launch the synthetic-dye industry. Béchamp also synthesized the first organic arsenical drug, arsanilic acid, from which Paul Ehrlich later synthesized salvarsan, the first chemotherapeutic drug.

Béchamp's rivalry with Pasteur was initially for priority in attributing fermentation to microorganisms, later for attributing the silkworm disease pebrine to microorganisms, and eventually over the validity of germ theory.

Béchamp claimed to have discovered that the "molecular granulations" in biological fluids were actually the elementary units of life. He named them microzymas—that is, "tiny enzymes"—and credited them with producing both enzymes and cells while "evolving" amid favorable conditions into multicellular organisms. Béchamp also denied that bacteria could invade a healthy animal and cause disease, claiming instead that unfavorable host and environmental conditions destabilize the host's native microzymas and decompose host tissue by producing pathogenic bacteria.

While cell theory and germ theory gained widespread acceptance, granular theories have been rejected by science. Béchamp's version, microzymian theory, has been retained by small groups, especially in alternative medicine.

He died 15 April 1908 in Paris.