The growing tendency to examine the blood for diagnostic purposes on occasions when it was formerly customary to resort to urinary analyses alone has shown certain advantages belonging to the newer technic. Not only do the proportions of certain constituents, such as the various types of nonprotein nitrogenous compounds — urea, uric acid, creatin and creatinin — give clues to the possibility of either metabolic or renal upsets; occasionally the undue accumulation of a substance like sugar in the blood will reveal an incipient disorder before the excess of carbohydrate finds its way through the kidney filter and manifests itself in a urinary test. Thus a pathognomonic hyperglycemia may be discovered in the absence of a detectable glycosuria.
Hitherto it has been the custom of exceedingly few clinical observers to examine the blood for evidences of the presence of bile salts and bile pigments. What the superficial examination of the