In 1793, Sir John Scott was promoted to the office of Attorney-General, in which it fell to him to conduct the memorable prosecutions for high treason against British sympathizers with French republicanism, among others, against the celebrated Horne Tooke. These prosecutions, in most cases, were no doubt instigated by Sir John Scott, and were the most important proceedings in which he was ever professionally engaged. He has left on record, in his "Anecdote Book", a defence of his conduct in regard to them.