Hallucinogens are a diverse group of drugs that cause an alteration in perception, thought, or mood. A rather heterogeneous group, these compounds have different chemical structures, different mechanisms of action, and different adverse effects.allucinogens are a diverse group of drugs that cause an alteration in perception, thought, or mood. A rather heterogeneous group, these compounds have different chemical structures, different mechanisms of action, and different adverse effects.
Which US President served the shortest term in office? William Henry Harrison, 9th President ,who died in office on April 4, 1841.served the shortest term of any president: March 4 - April 4, 1841. He served 30 days, 12 hours, andâ¦ 30 minutes. He died of pneumonia. William Henry Harrison only held office for 32 days.
James Madison, the fourth President of the United States, served  two four-year terms in the office, between  March 4, 1809 and March 4, 1817. He was preceded  in by Thomasâ¦ Jefferson and succeeded by James Monroe.