Editing Paracelsus (section)

===Toxicology===
Paracelsus extended his interest in chemistry and biology to what is now considered [[toxicology]]. He clearly expounded the concept of dose response in his ''Third Defence'', where he stated that "Solely the dose determines that a thing is not a poison." (''Sola dosis facit venenum'' "[[The dose makes the poison|Only the dose makes the poison]]")<ref>Paracelsus, dritte defensio, 1538.</ref> This was used to defend his use of inorganic substances in medicine as outsiders frequently criticized Paracelsus's chemical agents as too toxic to be used as therapeutic agents.<ref name=":3" /> His belief that diseases locate in a specific organ was extended to inclusion of target organ toxicity; that is, there is a specific site in the body where a chemical will exert its greatest effect. Paracelsus also encouraged using experimental animals to study both beneficial and toxic chemical effects.<ref name=":3" /> Paracelsus was one of the first European scientists to introduce chemistry to medicine. He advocated the use of inorganic salts, minerals, and metals for medicinal purposes. He held the belief that organs in the body operated on the basis of separating pure substances from impure ones. Humans must eat to survive and they eat both pure and impure things. It is the function of organs to separate the impure from the pure. The pure substances will be absorbed by the body while the impure will exit the body as excrement.<ref name=":8">{{Cite book|last=Hanegraaf|first=W.|title=Paracelsus (Theophrastus Bombastus von Hohenheim, 1493-1541)|publisher=Brill|year=2007|pages=509–511}}</ref> He did not support [[Hippocrates|Hippocrate's theory of the four humours]]. Instead of four humours, Paracelsus believed there were three: salt, sulphur, and mercury which represent stability, combustibility, and liquidity respectively. Separation of any one of these humours from the other two would result in disease.<ref name=":6" /> To cure a disease of a certain intensity, a substance of similar nature but the opposite intensity should be administered. These ideas constitute Paracelsus's principles of similitude and contrariety, respectively.<ref name=":6" />