SIMPLIFIED METHODS OF BLOOD EXAMINATION. THEIR PRACTICAL APPLICABILITY TO GENERAL DIAGNOSIS.

Laboratory aids to diagnosis, to be universally employed by the practicing physician, should be simple and rapid of execution, should require no costly or complicated paraphernalia, and should yield quicker and more positive results than purely clinical methods.

No period in the history of medicine has been free from attempts to find diagnostic clues in the examination of the blood; it was tried to interpret the rapidity of coagulation, the crusta phlogistica of eighteenth century physicians, the appearance of the blood as it flowed from the incised vein. With the development of microscopic technic and an insight into the truths of cellular pathology, valuable data relating to the morphology of the corpuscular elements of the blood in health and disease were discovered. During the last decade, especially through the efforts of German and American investigators—at their head Ehrlich of Berlin and Neusser of Vienna—a mass of purely empiric data on