Top 10 Most Disturbing Experiments of All Time

6. Elephants on Acid

In 1962, two psychiatrists from the University of Oklahoma injected LSD (in a dosage big enough to make 3,000 people hallucinate) into a 14-year-old male elephant named Tusko. The researchers initially thought that the acid would trigger a temporary form of madness in the three-and-a-half ton elephant. However, their hypothesis proved to be entirely wrong as the large creature in Lincoln Park Zoo in Oklahoma City trumpeted around its pen for a few minutes before dying shortly afterwards.