Important as is the subject of urinary acidity expressed in terms of ph, the negative logarithm of the hydrogen-ion concentration, a survey of the literature shows that little work has been done on the urine of infants. In the few cases reported (György1), the determinations were made on mixed twenty-four hour specimens, and in these apparently no special precautions were taken to prevent the loss of carbon dioxid, the importance of which has been pointed out by Marshall.2 Torres3 worked on the titratable acidity of the urine of infants fed different levels of protein; but no ph determinations were made.
In some work in our laboratory which included the determination of the total acidity and the ammonia content of infants' urines, it was observed frequently that the freshly voided urine was alkaline in reaction. Further investigations indicated that from time to time there was considerable