High blood ureas have been found in untreated cases (Schloss, 1918; Bessau, Rosenbaum and Leichtentritt, 1922; Cohen, Miller and Kramer, 1933), and Schloss considered that haemoconcentration was not enough to account for this finding. By means of the phenolsulphonphthalein test and Ambard's coefficient of urea excretion he showed that the function of the kidney was impaired in a group of infant...