Statutes which forbid the transaction of certain kinds of business on Sunday are valid.1 Statutes limiting the rate of interest which may be contracted for are valid,2 and accordingly a statute limiting the rate at which a banker can discount paper has been upheld.3 Statutes regulating the sale of patent-rights are valid,4 and a state statute requiring a vendor of a patent right to file a copy of his letters patent with the clerk of the court before selling such rights has been upheld.5