Cox was tried in Dublin in 1812 for publishing a production in favour of a repeal of the union between Great Britain and Ireland, and condemned to stand in the pillory and to be imprisoned for twelve months.
While Cox was in gaol under this sentence, Brenan quarrelled with him, went over to the opposite party, and started the 'Milesian Magazine, or Irish Monthly Gleaner.'
Brenan was ardently devoted to gymnastics, an expert wrestler, and occasionally showed symptoms of mental disorder.
An old bylaw of the college forbidding members to hold consultations with non-members was, according to Brenan, put in operation to curtail his practice.
The last number, which appears to have been that printed in 1825, contained a letter which Brenan addressed to the Marquis of Wellesley, lord-lieutenant of Ireland, advocating an inquiry into the administration of the Lying-in Hospital at Dublin, and stating the circumstances of his discovery in connection with turpentine.