Upon the death of any person before retirement which person shall have to his credit at least 10 years of service with the county or district, there shall be paid to his estate or to such beneficiary as he shall nominate by written designation duly executed and filed with the board, the sum of seven hundred fifty dollars ($750) to be provided from the contributions of the county or district.
This section shall not be operative in any county until such time as the board of supervisors shall, by resolution adopted by majority vote, make the provisions hereof applicable to the county.