If any writing which it is lawful for a clerk of the county court to admit to record, on proper acknowledgment or proof, has been or shall be lodged in his office, and has remained or shall remain therein six months without being acknowledged or proved so that it can be duly admitted to record, the clerk of the county court shall, for the preservation thereof, when required by any person interested, copy the same into a book separate from those in which writings properly acknowledged or proved are recorded, and keep an index to such book, as in the case of writings duly admitted to record. In case of the loss or destruction of any such writing, such copy shall be prima facie evidence of the contents thereof.