"Take of hydrate of potassa, of lime, each an ounce. Rub them together, and keep them in a well-stopped bottle."

Potassa cum Calce; olim, Causticum commune mitius, Edin. Potassa with Lime; formerly, Milder common Caustic.

1 Table-beer is sometimes recommended as the vehicle for administering it, but that liquor is seldom so free from acid as not to destroy the alkaline properties of the remedy.

2 Aq. Kali proeparatum, P. L. 1787. 3 Calx e Kali Puro, P. L. 1778.

"Take of the water of potassa, any quantity. Evaporate it to one third part in a covered iron vessel, then mix with it as much newly-slaked lime as will bring it to the consistence of a solid paste, which is to be preserved in a well-stopped vessel."

Potassa caustica cum Calce, Dub. Caustic Potassa with Lime.

"Evaporate water of caustic potassa to one fourth part; then add as much fresh-burnt lime, in powder, as will form a mass of a proper thickness, which is to be preserved in a well-stopped bottle."

The addition of the lime in these preparations renders the potassa less deliquescent, and consequently more manageable as an escharotic.