S. D. Vladychko. The effect of smoke on the nervous system and the body in general (with a focus on the prevention and treatment of acute and chronic poisoning). From 16 fig. on 2 tab. (From the laboratory of the clinic of the nervous. Bol. University of St. Vladimir in Kyiv). St. Petersburg 1909

Through experiments on rabbits, Dr. Vladychko establishes that in tobacco, in addition to nicotine, there is another toxic active substance of unknown chemical composition, which causes emaciation without noticeable anatomical changes in organs. Other symptoms of tobacco poisoning, regardless of the method of using it (smoking, sniffing, chewing), the author, based on his own research and literature data, refers to nicotine.