ment, the bladder is pushed forward and to the right, I feel that the left ureter is put on a stretch, while the right ureter angulates at the point where it traverses the parametrium. Why is it that pyelitis does not occur in every case of ureteral dilatation, in the presence of bacteria? The third determining factor is the lowering of the resistance of the organism. My studies have shown that in pregnant women there occurs a lowering of resistance to B. coli in about nine out of a hundred cases. The same phenomenon occurs in women following labor when there is excessive loss of blood. With the idea of pos¬ sibly preventing the occurrence of pyelitis by stimulating the peristaltic activity of the ureter, I now give pregnant women from the fifth month of pregnancy on calcium and potassium citrate in large doses and twice a week ephedrine orally and have reduced the occurrence of pyelitis to about Y per cent.Dr. E. G. Crabtree, Boston : There was no doubt that the cases to which Dr. Folsom referred were cases of cystitis without involvement of the upper urinary tract. Absence of upper urinary tract infection, while not proved in every case, was demonstrated in some. Residual urine during the course of pregnancy has been mentioned. After several years of following our cases in this regard we do not find residual urine except in rather unusual conditions and when there is a cystocele. Dr. Hofbauer has brought up many interesting questions. I assign a double cause for the dilatation of the ureter and pelvis in pregnancy. This is atony of the ureter and pelvis as a result of endocrine changes due to pregnancy and pressure applied by the uterus at the brim of the pelvis. New Orleans : The trail blazers in the field of postpartum urinary sepsis have been Hofbauer, Crabtree and Prather, and I wish to pay them respectful tribute. It has been the stimulating tenor of their work that has encouraged us to carry on with our study. We shall con¬ tinue our work with pyridium in order to report later whether we feel the same as some do or whether we shall retain our present high regard for this dye antiseptic. Certainly no con¬ vincing evidence has yet been advanced to show that pyridium, when administered in proper dosage and over a sufficient period of time, is not therapeutically effective. Davis attempted to solve this problem by showing that bacteria would grow in the voided urine of normal medical students who had taken various dyes by mouth. Helmholz substitutes rabbits for test tubes. Neither of these studies proves anything of clinical value. Physicians are not called on to treat test tubes or rabbits. Admitting the intricacy of investigations in dye therapy, we do not feel that the final evaluation of pyridium will be settled in the laboratory. Observational Ability.-Diagnostic success at the bedside may be held to depend firstly upon the historical analysis, and secondly upon our personal powers of observation, both of which are subject to the continual leaven of experience. Nothing is so variable as observational abi...