Nothing contained in this article shall be construed to apply to:
(1. The purchase, distribution, exhibition, or loan of any book, magazine, or other printed or manuscript material by any library, school, or institution of higher learning, supported by public appropriation;
Code 1950, § 18.1-236.2; 1960, c. 233; 1966, c. 516; 1975, cc. 14, 15.