phrynin

In another letter Dr. Lauder Brunton mentions that an active principle of the toad venom is probably of an alkaloidal nature. It has been called phrynin or bufidin. It appears to be a cardiac poison, acting in somewhat the way as digitalis; but its effects seem to resemble still more those of erythrophlœum, for the uncertain gait, convulsions and paralysis which it produces are precisely the symptoms produced by the erythrophlœum when used as an ordeal poison.

1892, “The Poison of the Toad”, in C. H. Hughes, editor, The Alienist and Neurologist, volume XIII, Reviews, Notes, Etc., page 398