Section, Pub. L. 91–510, title II, §242(a), Oct. 26, 1970, 84 Stat. 1171, provided that each meeting conducted by Senate Committee on Appropriations be open to the public except when testimony to be taken might relate to a matter of national security, tend to reflect adversely on character or reputation of witness or other individual, or divulge matters deemed confidential under other provisions of law or regulations.