§ 123. Jurisdiction of board to be continuing. The power and
jurisdiction of the board over each case shall be continuing, and it
may, from time to time, make such modification or change with respect to
former findings, awards, decisions or orders relating thereto, as in its
opinion may be just, except that, where the employer has secured the
payment of compensation in accordance with the provisions of section
fifty of this chapter, no claim for compensation or for death benefits
that has been disallowed after a trial on the merits, or that has been
otherwise disposed of without an award after the parties in interest
have been given due notice of hearing or hearings and opportunity to be
heard and for which no determination was made on the merits, shall be
reopened after a lapse of seven years from the date of the accident or
death. Nor shall any award of compensation or death benefits be made
against the special fund provided in section twenty-five-a of this
chapter or against an employer or an insurance carrier where application
therefor is made after a lapse of eighteen years from the date of the
injury or death and also a lapse of eight years from the date of the
last payment of compensation.