The court of county commissioners, board of revenue, or like governing body of DeKalb county shall have the power to levy and collect a special property tax, in addition to all other taxes now or hereafter authorized by the Constitution and laws of Alabama, of seven and one-half mills on each dollar's worth of taxable property in the county as assessed for state taxation during the preceding year, provided that the question of levying the tax, the purpose thereof, and the time such tax is proposed to be continued, shall have been first submitted to a vote of the qualified electors of the county and voted for by a majority of those voting at such election; and, provided further, that the total of all taxes levied for educational or school purposes in any school district of the county shall not exceed a total of fourteen and one-half mills on each dollar's worth of taxable property located in the district. If any proposal to levy the tax is defeated in any election, subsequent elections thereon may be held at any time. The election provided for herein shall be called, held, conducted, paid for, and governed otherwise in the manner provided for an election on the school district tax authorized in amendment III , article XIX, of the Constitution of Alabama, by article 7, chapter 10, Title 52, Code of Alabama (1940). The tax shall be collected in the same manner and under the same requirements and laws as the taxes of the state are collected. The proceeds of the tax authorized by this amendment shall be used exclusively for educational purposes, provided that the revenue derived from four and one-half mills of the total rate of taxation authorized herein shall be devoted only to purposes of capital outlay, and the revenue derived from the remaining three mills shall be devoted to current operating expenses.