The board shall proceed to examine the report and shall allow the collector a credit for such of the taxes so reported insolvent or delinquent, as it may be satisfied remain uncollected without the default of the collector, and no more. A list of the allowances shall be made out and certified by the clerk and transmitted to the auditor of public accounts, on or before the first day of September following, and shall be credited to the collector in his settlement with the auditor and chancery clerk.