Potassa Cum Calce. Potassa With Lime. Synonyms. - Vienna Caustic. Vienna Paste. Potassa, 500; Lime, 500. Rubbed together in a warm, iron mortar.


A grayish-white powder, deliquescent, having a strongly alkaline reaction, and responding to the tests for Calcium and Potassium. Solubility. - In diluted hydrochloric acid without leaving more than a small residue.