6.In this Act the expression “criminal lunatic” means
(a) any person for whose safe custody during His Majesty’s or the Lord Lieutenant’s pleasure His Majesty or the Lord Lieutenant or the Admiralty is authorised to give order; and
(b) any person whom the Lord Lieutenant or a Secretary of State or the Admiralty has, in pursuance of any Act, directed to be removed to an asylum or other place for the reception of insane persons:
Provided that a person shall cease to be a criminal lunatic if he is remitted to prison or absolutely discharged, or if any term of penal servitude or imprisonment to which he may be subject determines.