Peabody in 1912 (1) published a paper on the metabolism in pneu-monia, in which he reviewed the previous literature and studied among other factors the blood gases and acid-base balance. Since Peabody, a number of other investigators have studied the blood gases and the question of the existence and importance of acidosis in pneumonia. The present paper is a report of observations on these subjects, in which recently developed methods have made possible the attainment of more complete results and apparently have justified the drawing of deductions more definite in some respects than those attainable from previous data.

Peabody stated that" the high excretion of ammonia and the low excretion of sodium chloride are two of the most characteristic features of the urine during fever. The diminution of the carbon dioxide of the blood is apparently a constant accompaniment of fever." These results indicated a shift of some degree towards acidosis in the acid-base balance, but whether it was sufficient to be of clinical significance was at the time uncertain. Peabody states," The evidence points against the theory that the retention of sodium chloride in fever depends on acidosis... In diabetic acidosis and in experimental poisoning by mineral acids there is not a retention of bases as there is in pneumonia." In the gases of the venous blood much greater variations in oxygen than in carbon dioxide were found.