(From to burn). A cautery, either actual or potential. See Escharotica.

Cauterium Potentiate Ph. Edinb. The potential cautery of the Edinburgh Dispensary.

Take of Russian potash and quick lime, of each equal parts; of spring water three times the quantity of the whole; macerate them for two days, occasionally stirring them; then filter the ley, and evaporate it to dryness; put the dry mass into a crucible, and urge it with a strong fire till it flows like oil; then pour it out upon a flat plate made hot, and while the matter continues soft cut it into pieces of a proper size and figure, and keep them in glasses closely stopped.

This is also called lapis septicas. It is a strong and sudden caustic, but it deliquesces too soon in the air, and runs beyond its proper bounds; indeed, the suddenness of its action depends on its disposition to liquefy. But this inconvenience is avoided in the calx cum kali puro. Ph. Lond. 1788.