What is the blood?

What it is

• The blood is an opaque, rather viscid fluid, of a bright red or scarlet color when it flows from the arteries, of a dark red or purple color when it flows from the veins. It is salt to the taste, and has a peculiar faint odor and an alkaline reaction. Its specific gravity is about 1.06, and its temperature is generally about 37° C., though varying slightly in different parts of the body. General Composition of the Blood.
• —Blood consists of a faintly yellow fluid, the plasma or liquor sanguinis, in which are suspended numerous minute particles, the blood corpuscles, the majority of which are colored and give to the blood its red tint. If a drop of blood be placed in a thin layer on a glass slide and examined under the microscope, a number of these corpuscles will be seen floating in the plasma.
• The Blood Corpuscles are of three kinds: (1) colored corpuscles or erythrocytes; (2) colorless corpuscles or leucocytes; (3) blood platelets.