When such bonds shall be sold or exchanged for the evidence of indebtedness of the county, such evidence shall be canceled in such manner that the same cannot again be used, and memorandum of all such evidences of indebtedness shall be made in the minutes of the board, so that the same may be identified. Such canceled vouchers shall be sealed in an enclosure and filed for future reference.
Fla. Stat. § 130.09