prunella salt
Webster's Dictionary (GCIDE)
Prunella \Pru*nel"la\, n. [NL., perhaps from G. br[ae]une quinsy, croup.] (Med.) (a) Angina, or angina pectoris. (b) Thrush. [1913 Webster]
Prunella salt (Old Chem.), niter fused and cast into little balls. [1913 Webster] Prunella