The very fact that it is produced and consumed by the human brain every time one sleeps for long periods of time is enough evidence. However, a simple google search for DMT (dimethyltriptamine) and Wikipedia can provide sufficient info on this chemical. Well, I don't want to end up telling everyone where to get it but other than extracting it from the brain of animals and humans (no don't do that), there are a wide variety of plants that have DMT in them. A simple google search will suffice as well but if you must know Mimosa hostilis, Diplopterys cabrerana, Psychotria viridis, and the ayahusca plant. It is also said that some species of grass can also yield small amounts of DMT. A hallucinogenic DOES NOT cause hallucinations. Another google/wiki search into the term will prove just that. Hallucinations, strictly speaking, are perceptions that have no basis in reality, but that appear entirely realistic. A typical "hallucination" induced by a psychedelic drug is more accurately described as a modification of regular perception, and the subject is usually quite aware of the illusory and personal nature of their perceptions. I know of this personally because I've been able to induce these myself without the aid of drugs through focus, meditation, and trance....however, they're no where near as powerful. Leading to the second part of this argument: Since it does not cause hallucinations and simply a change in perception, one is fully aware of their actions and words. Therefore, one isn't drunk or devoid of logic. As stated before, a hallucinogen does not cause hallucinations. One still is in tune with reality and what is going on and is able to make appropriate decisions. Tobacco is something that causes diseases in the gums and lungs. DMT causes no such thing and as stated before, is produced in the human brain EVERY NIGHT. Therefore, it is not harmful and non-addicting.