§ 479. Soliciting business on behalf of an attorney. It shall be unlawful for any person or his agent, employee or any person acting on his behalf, to solicit or procure through solicitation either directly or indirectly legal business, or to solicit or procure through solicitation a retainer, written or oral, or any agreement authorizing an attorney to perform or render legal services, or to make it a business so to solicit or procure such business, retainers or agreements.