Section 5. That all penalties and costs received by the said State Board of Agriculture for violations of the said act of May twenty-one, Anno Domino one thousand eight hundred and eighty- five, and of other acts now enacted or hereafter to be enacted, prohibiting or regulating the adulteration or imitation of butter, cheese or other dairy products, shall be appropriated by the said board to the payment only of the necessary expenses incurred by the said Dairy and Food Commissioner and his assistants and agents in the investigation, discovery and prosecution of violations of the said act.