The person who is often referred to as the father of toxicology for his first textbook on poison is:

Matthew Joseph Orfila, a spanish chemist, wrote the first textbook of poison in 1814. Orfla extracted arsenic from human tissue using a procedure for identification developed by James Marsh. The evidence was used in a cou in 1940 to convict Marie Lafarge of homicidal poisoning. Robe Christison was the father of British Toxicology and Alexander Gettler is known as the father of American Toxicology. Ref: Textbook of Forensic Medicine & Toxicology: Principles & Practice, 4/e by Vij, Page: 562