This paper is a report of a study of the blood diazo test and of the conclusions deduced. Blotner and Fitz,1 the first workers in this country, reviewed the papers of Andrewes2 and Hewitt3 of England, of Becher4 of Germany and of Rabinowitch5 of Canada. Their work and the recent publication of the studies of Patch and Rabinowitch6 have been reviewed by us.
Andrewes,2 while performing the van den Bergh test for bilirubin in the blood, noted a deviation from the normal color. He then added alkali to the end-product and obtained a pink coloration instead of the green of azobilirubin; this occurred only in persons with markedly damaged kidneys. He also found a blood bilirubin less than normal in amount in the same patients. Van den Bergh7 recognized a hypobilirubinemia in chronic nephritis. Beth,7 another German worker, differentiated malignant nephrosclerosis