There may be organized in any city in the State of Oklahoma voluntary associations to be known as cotton exchanges, grain exchanges, boards of trade or similar institutions to receive and post quotations on cotton, grain, stocks, bonds and other commodities for the benefit of its members and other persons engaged in the production of cotton, grain and other commodities. Such associations shall be composed of not less than forty (40) members and shall adopt a uniform set of rules and regulations not incompatible with the laws, as are usual for such associations. They shall open their books to the inspection of proper courts and officers of the law when required.