Dr. Tomis Leed was one of the scientists working on the naquadria bomb on the planet Kelowna and was introduced in the episode, 5.21 "Meridian".
Dr. Leed was present when there was an accident during an experiment to measure the power of the radioactive mineral naquadria, but sought out safety instead of working on a solution to dismantle the project before the core went critical. This was the accident which the Kelownans tried to blame on Daniel Jackson as sabotage when in reality, it was Daniel who saved the planet by removing the core and thus exposing himself to the lethal radiation. (5.21 "Meridian")
During the year that followed the accident, Dr. Leed was committed to a mental facility because he had become schizophrenic. Another scientist was also committed before that for the same symptoms. After Dr. Leed showed the symptoms, it was determined that long-term exposure to the naquadria radiation, without the proper shielding, led to this mental disorder. Finally, a third scientist, Dr. Kieran, with whom Jonas had worked on the naquadria project for six years, also fell to the illness. (6.07 "Shadow Play")
--DeeKayP 13:05, 10 Oct 2004 (PDT)