REPLY FROM DRS. BROWN, PEARSE, PYRGOS, LIU, TOGIAS, AND PERMUTT

To the Editor : We accept the inference of Professor Stanescu ([2][1]), an authority on the measurement of pleythysmographic lung volumes, that the frequencies used by us for the measurements ([1][2]) were in a range where they could have been overestimated. We do not believe, however, that such an