THE GREAT number of provocative tests used in the diagnosis of glaucoma is itself an indication that none of them is entirely adequate. Therefore we regarded Grant's1 aqueous-flow test with considerable interest, since it appeared to be a useful and efficient method of helping in the diagnosis of glaucoma. In an attempt to evaluate the role of this new approach to the problem of glaucoma, we undertook the present study. METHOD The theory and the technique of this test have been extensively discussed by Grant2 and Friedenwald3; it is sufficient, therefore, to mention them only briefly. We followed Grant's method and employed either the five-minute or the abbreviated, four-minute, test with a recording galvanometer. We measured the facility of aqueous outflow (cubic millimeters per minute) on 400 eyes of 301 patients, performing 500 tests over a one-year period (December, 1950 to December, 1951). Most of the patients