Benjamin Franklin was a famous American statesman, inventor, scientist and diplomat who lived in London for 16 years. He was also a member of the Hellfire Club, an exclusive club for high-society rakes who met regularly to engage in immoral and political activities12. One of his friends and mentors was William Hewson, a British surgeon and anatomist who ran an anatomy school in London34.
In 1998, when Franklin’s old house at 36 Craven Street was renovated, workers found a secret room under the garden that contained over 1,200 pieces of bone from at least 15 people56. Six of them were children. The bones were dated to the time that Franklin lived there, around 1760-177656. Forensic investigations showed that the bones had signs of surgical cuts and holes in some skulls56. It is believed that Hewson used the basement as his anatomy lab and buried the remains there after he was done with them56. He obtained cadavers from graveyards or from the gallows at the end of the street56.
The discovery of the bones sparked a lot of interest and controversy among historians, scientists and the public. Some speculated that Franklin was involved in some kind of dark ritual or experiment in his basement, but there is no evidence to support that claim56. Others suggested that he was aware of Hewson’s activities but did not interfere or condone them56. The truth is probably somewhere in between: Franklin may have been curious about anatomy but not necessarily part of Hewson’s illegal business56
https://en.wikipedia.org/wiki/Hellfire_Club