2. A distinction was formerly made in respect of contracts, between mala prohibita and mala in se; but that distinction has been exploded, and, it is now established that when the provisions of an act of the legislature have for their object the protection of the public, it makes no difference with respect to contracts, whether the thing be prohibited alsolutely or under a penalty. 5 B. & A 5, 340; 10 B. & C. 98; 3 Stark. 61; 13 Pick. 518; 2 Bing. N. C. 636, 646.