As an additional and supplementary method of paying and liquidating the claims, accounts or charges composing the aforesaid indebtedness, the governing authorities of municipal corporations, parishes, and school boards may fund the avails of all or any portion of the specified two mills tax into negotiable certificates of indebtedness.  The avails shall be sufficient in amount to pay the principal and interest on the certificates which shall be secured exclusively as to payment as hereinbefore provided and which shall be in such denomination as the issuing body may prescribe by resolution or ordinance promulgated once in its official journal, or in any other newspaper in general circulation in the parish where the issuing body is situated.