Whenever a common carrier by rail incorporated under the laws of this state shall apply to the department for authority to issue any stock requiring the approval of the department, the stockholders shall not become individually liable for debts and contracts of the corporation under N.H. Rev. Stat. § 296:30, if the amount of stock which the department authorized the corporation to issue upon any such application is paid in and a certificate of the treasurer and a majority of the directors to that effect is executed, filed and recorded in the manner provided by N.H. Rev. Stat. § 296:30 within 90 days after the filing in the office of the secretary of state of the order of the department authorizing the issue of such stock; provided that, in cases where such stock is an increase of prior capital, the whole amount of the prior capital as theretofore fixed and limited by the corporation, or so much thereof as the stockholders have voted to issue, or as the department has authorized to be issued, has also been paid in and that the certificate so filed by the treasurer and directors shows that fact.