Argyrol

Barnes did not invent Argyrol, but it was his idea to find a way of denuding silver protein of its caustic qualities without losing power as an antiseptic.

Through this analysis, chemists determined that Bacon, as well as other spies, was using Argyrol, the commercial name for a silver salt of a protein mixture sold as a light brown powder soluble in water.

After a few years, Barnes bought out his partner, and Argyrol became his property alone.