It is a well-settled principle that when any act is declared by statute to be criminal, a contract calling for the performance of such an act is illegal and void. The early English authorities on this point are fully collated in Wheeler v. Russell (17 Metc., Mass., 258), and the later English and American cases may be found in “American and English Cyclopædia of Law,” title “Contracts,” Vol. III., p. 872 _et seq._; see also _id._, Vol. XVIII., p. 440. Further consideration of the validity of contracts for medical and surgical services will be had hereafter. A full synopsis of the statutes of the different States regulating the licensing of physicians and surgeons in force at the time this volume goes to press will be placed in another chapter. In a suit between a person who has performed medical and surgical services, and one who employed him, it is said that the person performing the services is presumed to have been licensed to do so.[157] If the State sues for a penalty, a different rule is claimed to prevail.[158] HOW MAY A DIPLOMA OR LICENSE BE PROVED IN A COURT OF LAW? It is evident from the foregoing considerations that in any proceedings to punish for practising without license or legal authority, and in actions to recover payment for professional services in the States and countries, where a license or diploma of a regularly chartered school or college is required by statute to entitle the person to practise, it may become important to establish—first, the legal authority to grant the license or diploma; and second, the genuineness of the license or diploma produced. It frequently happens that the diploma or license has been obtained in another State or country. Under the New York statutes, especially the laws of 1880 and 1890, it was made necessary to file a diploma. When it had been issued by a chartered school of another State it must be certified to by some lawfully incorporated medical college in this State, before being received for filing, or regarded by the law as conferring upon its possessor the right to practise in that State. As to the chief element of authenticity, namely, the legal incorporation or authority of the body or institution granting the diploma, it is clear that the act of incorporation itself would be the best evidence of the incorporation of the college or school, and a special act granting the power to license to a board of censors or other official body or board would have to be produced to show the right vested in that board or body to grant a license. In Georgia it has been held (Hunter _v._ Blount, 27 Ga., 76), that to prove a diploma given to a physician in another State, the existence of the college, and the fact of its being a chartered institution, must be shown by producing its act of incorporation.