1. it was not until the enactment of the 1952 Patent Act that a specific non-obviousness requirement was added. See Patent Act of 1952;Burstein;Visual Invention, supra note 28,1842
2. Act of July 8, 1870, ch. 230, � 71, 16 Stat;REV. STAT. �,1861
3. codified as 35 U.S.C. � � 101 et seq;Stat,1952