Bismuth salts have been used for many years for diagnostic and therapeutic purposes, but their effects after absorption on the human system have received only scant attention. This is all the more remarkable in view of the fact that the other heavy metals have been the object of careful study in systemic poisoning, and are known to produce well recognized symptoms. Edsall has a very exhaustive article on metallic poisonings in Osler's "System of Medicine," but makes no reference to the toxicity of bismuth. The subject, however, has not been neglected so far as experimental work is concerned, as shown by the literature. As long ago as 1786, there were reports of vomiting, twitchings, dizziness and somnolence due to the ingestion of these salts. It was thought that these symptoms were due to impurities, particularly arsenic and lead, and it is possible that such was the case at that time.
HIGGINS WH. SYSTEMIC POISONING WITH BISMUTH. JAMA. 1916;LXVI(9):648–650. doi:10.1001/jama.1916.02580350036015