It shall be the duty of each vender of or dealer in goods, wares, and merchandise who has thus commenced business on or after May first of each year to apply to the mercantile appraiser for a proper blank, to be prepared by the Department of Revenue, to fill up the same, and return it to the mercantile appraiser of the proper county within forty days from the date of commencing said business, with an affidavit certifying to the correctness of the amount of business transacted during the first month in which said business has been operated. If the mercantile appraiser is dissatisfied with the returns so made by the vender or dealer he shall ascertain and assess the mercantile license tax according to the best ascertainable information concerning the whole volume gross of business transacted during the first month said business was operated. If any vender of or dealer in goods, wares, and merchandise refuses to make such return as required by this act to the mercantile appraiser when requested so to do, it shall be the duty of the mercantile appraiser to report the same immediately to the county treasurer, whereupon it shall be the duty of the county treasurer to require the owner or business manager to appear before him in person with the books and accounts of his mercantile establishment for interrogation and examination, and the county treasurer shall have power to issue subpoenas and attachments to be served by any constable or sheriff to compel the attendance of the owner or any clerk, bookkeeper, or officer connected with the said business, and to compel the production of such books and papers as he may deem expedient to secure the information necessary to ascertain and fix the amount of the business transacted during the month when the said vender of or dealer in goods, wares, and merchandise has been in business.