T WO procedures commonly used in testing the patency of the Fallopian tubes are tubal insufflation and hysterosalpingography. In the former, carbon dioxide or air is insufflated through the cervical OS. Its escape into the abdominal cavity is verified by suprapubic auseultation, the fall in the manometric pressure, the production of shoulder pain when the patient assumes the erect posture, or the radiologic demonstration of a gas meniscus under the diaphragm. Meigs and Sturgisl stress the fact that unless the patient has unmistakable shoulder pain on resuming the erect position after the test, such test must be considered a failure and must be repeated, even though a drop in the manometric pressure and suprapubic auscultation suggest the passage of the gas. Crossenx advises that in doubtful cases an x-ray be taken to demonstrate the presence of a subphrenic pneumoperitoneum. These absolute evidences of the presence of the insufflated gas in the abdominal cavity are essential because of the difficulties of detecting the leakage of gas, especially at the junction of the cannula with the external OS. Hysterosalpingography may be done after tubal insufflation has indicated obstruction in the tubes.3 In hysterosalpingography a radiopaque substance is injected into the uterine cavity. The filling of the uterus and tubes and the progress of the substance may be observed under the fluoroscope. X-ray films are made during and subsequent to the procedure for record and further study. As Feiners has stated, such injection of a radiopaque substance is not an inocuous procedure and as a diagnostic method these injections carry a certain morbidity and mortality, although small.4 When Lipiodol is used a foreign substance of slow or minimal assimilation is introduced into the tubes, the pelvic and abdominal cavities. Rubina has demonstrated radiopaque deposits at one month to a year and longer in the tubes, the pelvis, and upper abdominal cavity and also the production of Lipiodol granulomas in the Fallopian tubes. The accidental injection of ovarian and pelvic veins with the production of anaphylactoid reactions and the presence of pulmonary embolism have been reported also.% 6, r TO avoid such hazards and unrertainties, the author reports his use of sterile normal saline to demonstrate tubal patency. Procedure.-The test is performed in the preovulation period. The cervix is exposed with a Graves speculum. It is cleaned and swabbed with an antiseptic solution. Using a Jareho pressometer (or any other similar instrument) and a standard insufflation cannula, 20 to 30 C.C. of sterile normal saline are injected under manometric pressure. Since the injected medium is a liquid, any leak in the circuit is easily detected. If after the instillation the vagina is dry and no visible leakage has occurred at any instrumental connection, it is obvious that any utilized number of cubic centimeters of the normal saline must have progressed upward. Constant observation of the manometer is made in the usual manner and for the usual records and inferences, as in the routine insufflation of gas. The use of a physiologic solution, sterile normal saline, to determine tubal pat,enry has certain advantages over gas and/or radiopaque substances: