A mixture of quick-lime (2 parts) and caustic potash (1 part) is sometimes a useful es-charotic for superficial forms of epithelial cancer; it should be mixed, just before using, with sufficient alcohol to form a paste ("Vienna paste"), and spread over a suitable aperture in diachylon plaster previously placed on the part; its action begins immediately, and lasts for about half an hour; the eschar is dark-colored, and separates in from ten to twelve days. A proportion of 6 parts of lime to 5 of potash is recommended by some authors, and for application to deeper-seated parts, such as the neck of the uterus, a combination of 1 part of lime with 2 of potash is used, especially by French surgeons ("caustique Filhos"); it is fused by heat, and poured into a small mould of lead, which can be cut away as the caustic is required.