For a number of years there has been a good deal of interest in the retention of chloride during pneumonia and in the low concentration of chloride in the blood. In 1869, Leyden1 concluded that the tissues must contain more water during fever than normally, and this has been confirmed by later analyses of the tissues themselves. Hutchinson2 reviewed the earlier work on chloride metabolism during pneumonia and showed that in adults about 2 Gm. of sodium chloride a day may be retained during the fastigium, and that this is released from one to two days after the crisis. He showed that the pneumonic exudate could account for only from 5 to 7 Gm. of sodium chloride, which is about only one-half the amount retained.
Peabody3 confirmed the low concentration of chloride in the blood and showed that it was concomitant with retention of chloride. He was