In its widest sense, this term may denote any poison or toxicant; but as used in pathology and medical jurisprudence ft signifies, in general, any diffusible alka-loidal substance (as, the ptomaines, abrin, brucin, or serpent venoms), and in particular the poisonous .products of pathogenic (disease-producing! bacteria
Source: Black's Law Dictionary 2nd Ed (1910)