PHARMACOLOGICAL ACTIONS OF ACRIDINE DERIVATIVES, WITH ESPECIAL REFERENCE TO THOSE OF ACRIFLAVINE AND ATEBRIN

1. Acriflavine in bacteriostatic concentrations produces no toxic effects on the isolated frog's heart, and indeed prolongs rather than shortens the survival period. 2. Out of seventeen acridine compounds tested on the isolated frog's auricle, only one, a chloro compound, was markedly toxic. 3. The majority of the acridine compounds tested antagonised acetyl choline. Some compounds (e.g.acriflavine and atebrin) showed this action with frog's tissues and mammalian tissues. Other compounds (e.g. 2‐amino‐acridine monohydrochloride) only showed this action with frog's tissues. 4. No obvious relation could be shown between chemical structure and pharmacological action.