“ That court was of opinion that the provisions of the Kansas statute did not trench upon the Federal power nor interfere with the rights secured to patentees by Federal law. The opinion does not assert that a state statute can interfere with the right of a patentee to sell or assign his patent, nor that it can take away any essential feature of his exclusive right, but, as is stated, the provisions in the act have no such purpose or effect; that 'they are in the nature of police regulations designed for the protection of the people against imposition and fraud. ”

“ In some of the cases holding such statutes void it is said that it is unfortunately true that many frauds are committed under color of patent rights, and that the patent laws are not so framed as to secure the public from being cheated by worthless inventions; but, notwithstanding that, they hold statutes of the nature of the one under consideration to be void, as trenching upon the rights of the owner of a patent secured by the Constitution and laws of the United States. ”

“ There is no discrimination which can be properly so called against property in patent rights, exercised in such legislation. It is simply an attempt to protect the citizen against frauds and impositions which can be more readily perpetrated in such cases than in cases of the sale or assignment of ordinary property. ”

“ The expense of filing copies of the patent and the making of affidavits in the various counties of the state in which the owner of the rights desired to deal with them is not so great, in our judgment, as to be regarded as oppressive or unreasonable, and we fail to find any other part of the act which may be so regarded. Some fair latitude must be allowed the states in the exercise of their powers on this subject. It will not do to tie them up so carefully that they cannot move, unless the idea is that the states have positively no power whatever on the subject. ”