In American Society for Testing Materials v. Board of Revision of Taxes, 423 Pa. 530, 225 A.2d 557 (1967) (ASTM), the Supreme Court upheld the Society's exemption as a purely public charity over the City of Philadelphia's objection that its principal beneficiaries were its membership, which was not open to the public, and that the Society had no contact with the public save through its library, which was not a general interest library and rarely used by the public. The Court concluded that the Society primarily benefited the general public. The Court has since reinforced the concept that a purely public charity can provide members of the general public with resources that would not otherwise be within their reach, and that "it is fully consistent with the fundamental character of a purely public charity to benefit the general public." Unionville-Chadds Ford School District v. Chester County Board of Assessment Appeals, 552 Pa. 212, 714 A.2d 397 (1998). See also Appeal of Sewickley Valley YMCA, 774 A.2d 1 (Pa. Cmwlth. 2001).