Paper, 'An observation of one hemisphere of the braine sphacelated: and of a stone found in the substance of the braine itsself [sic]' by Edward Tyson Tyson describes the autopsy of a man who had, in the months preceding his death, been badly bruised on the head and subsequently suffered from convulsions and vomiting. In the autopsy, the man's left hemisphere was found to have necrotised and a 'chalky stone' was found within the brain's tissues. Subject: Anatomy / Medicine Published in Philosophical Transactions as 'An observation of one hemisphere of the brain sphacelated, and of a stone found in the substance of the brain its self'. Read to the Royal Society on 12 May 1697. 12 December 1688