Escharotics were introduced to Western medicine in the 1930s by Frederic Mohs, who was then a medical student at the University of Wisconsin, Madison, investigating tissue fixation as part of a new surgical treatment for cancer. Mohs chose zinc chloride as a proper tissue fixative based on studies he performed on cancerous and normal rat tissues. Mohs consulted with a pharmacist to create a paste that could be applied to the skin, and the final product, Mohs paste, contained zinc chloride as a fixative, as well as antimony trisulfide for suspension and bloodroot as an organic stabilizer.8 Mohs proposed that this paste, applied in a carefully calculated manner that accounted for the tumor's depth and diameter, would fix tumor in tissue over a 24-hour period. This process enabled the surgeon to remove a fixed specimen and, following sectioning and staining, immediately review the histologic findings to assess tumor involvement of the surgical margin. The paste application, fixation, and excision of the tumor was repeated daily until the microscopic examination finding was negative for tumor.9 It should be clarified that Mohs used zinc chloride only as a fixative and Sanguinaria only as an organic stabilizer for his fixative paste. The primary procedure undertaken by Mohs was surgical excision. He coined his technique "chemosurgery," and thus began the long-storied history that has culminated in the widespread use of micrographic surgery