Transfers of the certificates of the bonded debt of the state shall be made in the office of the board of commissioners of the sinking fund by the owner thereof, his agent, or attorney in fact. A power of attorney for that purpose may be written or printed on the certificate of the bonded debt, and attested by one subscribing witness, authorizing any person to transfer such certificate. A certificate of the bonded debt in the name of a deceased person may be transferred by his legal representative in person, or by power of attorney, upon full proof of the representative character of such person, established by producing and filing letters testamentary or letters of administration properly authenticated according to the laws of the state, territory, district, or government where the deceased owner died and letters testamentary or of administration were granted. When a transfer of any part of the bonded debt is made, the secretary of the board shall enter such transfer in the stock ledgers of such bonded debt to the credit of the person to whom transferred.