No person shall sell, either by wholesale or retail, any of the poisons enumerated in § 21-30-7, without distinctly labeling the bottle, box, vessel, or paper and wrapper or cover in which the poison is contained with the name of the article, the word “poison,” and the name and place of business of the seller; and every registered pharmacist selling or dispensing any of these poisons shall first enter in a book, to be kept for that purpose only, and subject always to inspection by the board of pharmacy or any officer or agent of the board or other proper authority, and to be preserved for at least five (5) years, a record of the sale or dispensing; provided, that if any of the poisons form a part of the ingredients of any medicine or medicines compounded in accordance with the written prescription of a medical practitioner, the medicine need not be labeled with the word “poison”; but all prescriptions, whether or not composed in part or in whole of any of these ingredients, shall be carefully kept by the pharmacist on a file or in a book used for that purpose only and numbered in the order in which they are received or dispensed, and every box, bottle, vial, vessel, or packet containing medicines so dispensed shall be labeled with the name and place of business of the registered pharmacist so dispensing the medicine, and be numbered with a number corresponding with that on the original prescription retained by the pharmacist on the book or file. The prescriptions shall be preserved at least five (5) years and shall be open to the inspection of the writer of them, and a copy shall be furnished free of expense whenever demanded by either the writer or the purchaser.