Provided that noe Officer or Soldier shall have the benefit of this Act that shall not prove his Service as aforesaid either by a Certificate under the Hand and Seale of some Feild Officer and two Commission Officers of the Regiment wherein he served, or some Generall Officer of the Army certifyeing his knowledge of the Service aforesaid, and the said Certificate to be proved by one Witnesse at least to be a true Certificate, or for default of such Certificate by the Oathes of two credible persons at least.