Although the knowledge of a lessened concentration of chloride in the urine of patients with fever1 seems to have antedated Redtenbacher's2 report, he appears to have been the first to have definitely connected pneumonia with a regularly diminished excretion of chloride. Ever since then, the subject has attracted considerable attention. The original observations have been amply confirmed and extended.3 Many studies on the metabolism of patients with pneumonia have been made, but, aside from the changes due to the increased protein catabolism, no change comparable to that in the excretion of chlorine (and sodium) has been observed, nor have these numerous investigations furnished a satisfactory explanation for the observed changes in excretion of the chloride.
One of the first hypotheses to have been advanced in explanation of this condition appears to be that of Traube,4 who suggested that the low excretion of chloride was due to