(fallen london stamps by you see, the good doctor has a bunch of points in kataleptic toxicology, but he put most of them into the "make esoteric medicines" tree, with a side of "metabolize any poison" for funsies. he had none left over for the actual "make poisons to kill people" tree
that being said, the esoteric medicine tree DOES have some handy offensive utility traits, like "make very very effective paralytic drugs"