If it appears that the name of any person has been signed to any bond or other obligation as surety thereon without his or her consent, or that the name of any person which has been at any time properly signed as surety to any bond or obligation has been erased or withdrawn therefrom before delivery thereof, without the consent of other persons signing the bond or other obligation as sureties prior or subsequently to the erasure or withdrawal, the signing without authority or erasure or withdrawal shall not have the effect of rendering the bond or other obligation void as to all of the other obligors thereon. The sole effect thereof shall be to diminish the extent of the liability of the sureties thereon, other than those whose names may have been so signed without authority or erased as aforesaid, by an amount equal to that which would have been contributed to discharge the common liability by the persons whose names were so signed without authority, or erased as aforesaid, had the want of authority, or erasure not existed.Acts 1891, No. 55, § 1, p. 91; C. & M. Dig., § 8283; Pope's Dig., § 10860; A.S.A. 1947, § 34-328.