A recent description1 of a very ingenious adaptation of the mercurial blood pressure manometer to the study of cerebrospinal fluid pressure suggests this note. The method here described is well known, but in view of the use of mercurial manometers deserves to be even better known. I first saw the method used by Dr. Harvey Cushing, and have since found it valuable on the mission field, where simple tools must be used when possible.
After the lumbar (or ventricular) puncture has been performed, a sterile piece of glass tubing, 2 feet long and with a small caliber, is connected with the needle by means of a sterile piece of small rubber tubing, 1 or 2 inches long. The height to which the spinal fluid rises above the needle may be read by a ruler placed beside the glass tubing. If one wishes to remove some of the spinal