In these busy days, a period which in the history of medicine, will be known as "The Age of the Specialist," the general practitioner must hail with delight a branch of the science so rapidly opening up before him. Let us see what can be done with only a microscope, the possession of which instrument should be the first aim of every physician.
A drop of blood from the lobe of the ear, hastily touched by the center of a clean cover-glass, deposited on a warm, highly-polished slide and a single layer of corpuscles thus spread. With a little experience one can readily tell if the drop is more concentrated than normal or is hydremic. Examination with a one-twelfth inch oil immersion will determine the relative size of the red corpuscles, their shape, the approximate number of white to red, and detect the presence of parasites; a few minutes' search