Section 36. Objections to the competency or credibility of the deponent and to the admissibility of any questions asked of or answers made by him may be made when the deposition is produced in the same manner as if he were personally examined as a witness at the trial; but if a deposition is taken upon written interrogatories annexed to a commission, all objections to an interrogatory shall be made before the commission issues, and unless the interrogatory is withdrawn shall be noted in the deposition, otherwise they shall not be allowed.