Each person engaged in the practice of medicine, chemistry, bacteriology, roentgenology, or other similar profession, except chemists, bacteriologists, and roentgenologists employed full time by physicians, nonprofit scientific institutions, and hospitals, and except doctors employed exclusively by a medical college, shall pay the following annual license tax: In cities or towns of over 5,000 inhabitants, $25; 1,000 to 5,000 inhabitants, $10; all other places, whether incorporated or not, $5, but no license tax shall be paid to the county. If such business is conducted as a firm or as a corporation in which more than one person is engaged, each person so engaged shall pay the license tax as above stated. The license tax imposed by this section shall not apply until such person shall have practiced his or her profession as long as two years. Two fifths of the annual license tax herein levied shall remain in the Treasury and shall constitute a separate fund to be disbursed by the Treasurer as follows: All of such fund arising from licenses paid in each of the separate counties of the state shall be set aside in a separate fund for such county and shall be disbursed by the Treasurer, on the order of the board of censors of the medical society of such county, if there is such organization in such county.