Every person, association or corporation, or the agent of any person, association or corporation, engaged in the business of milling, sampling, concentrating, reducing, shipping or purchasing ores, who keeps or uses any false or fraudulent scales or weights for weighing ores, who keeps or uses any false or fraudulent assay scales or weights for ascertaining the assay value of ore, knowing them to be false, is guilty of a misdemeanor, and is punishable by a fine in any sum not exceeding $1000, or by imprisonment in the county jail for a term of not more than one year nor less than one month, or by both such fine and imprisonment.