In 1899, he went into business with German chemist Hermann Hille (1871-1962), and created Argyrol, a silver nitrate antiseptic which was used in the treatment of ophthalmic infections and to prevent newborn infant blindness caused by gonorrhea. The two left H.K. Mulford and Company to organize a partnership called Barnes and Hille. This new company was founded in 1902. Hille ran production and Barnes ran sales. The company prospered financially, but the relationship between the two men waned. In 1908 the company was dissolved. Barnes went on to form A.C. Barnes Company and registered the trademark for Argyrol. In July 1929 Zonite Corporation of New York bought A.C. Barnes Company. The move was well timed as the stock market crashed in October that year.