In case any person so elected county treasurer shall be declared ineligible, refuse to give bonds agreeably to law, die, resign, remove from the county, or be removed from office on account of any delinquency or misdemeanor, it shall be lawful for the county commissioners to appoint a suitable person to fill said office until the expiration of the term for which such county treasurer shall have been elected; and the person so appointed shall conform and be subject to the laws of this Commonwealth in relation to county treasurers, and be subject to like removal: Provided, no person shall be appointed, declared by law to be ineligible to election.