The increasingly successful application of chemical methods to the clinical examination of the blood has decidedly enhanced the diagnostic and prognostic possibilities of practical medicine. Estimations of blood sugar, nonprotein nitrogen and chemical factors, such as the carbon dioxid combining power of the plasma conditioned by acidosis, stand out as conspicuous examples of the service of modern biochemistry in clinical work. Numerous additional instances might be cited in which the deserts of new procedures and the merits of new analytic methods applied to the study of the blood must remain in abeyance until more facts and further critique are available. In illustration one may recall the content of cholesterol and other lipoids, of amino-acids and other simple nitrogenous compounds in the blood in relation to health or disease.
The existence of a variable starch-digesting power on the part of the urine has long been known. In recent years, attempts have