BLOOD, the red circulating fluid in the bodies of man and the higher animals. It is formed from chyle and lymph when these substances are subjected to the action of oxygen taken into the lungs by the process of inspiration. It is the general material from which all the secretions arc derived, besides which it carries away from the frame whatever is noxious or superfluous. In man its temperature rarely varies from 36.6° C. =98° F., but in birds it sometimes reaches 42.8° C.=109° F. The blood in reptiles, amphibia, and fishes, and the circulating fluid in the invertebrata, is cold, that is, in no case more than a little above the temperature of the sur rounding medium. The vessels which conduct the blood out of the heart are called arteries, and those which bring it back again veins. The blood in the left side of the heart and in the arteries, called arterial blood, is bright red; that in the right side of the heart and in the veins, called venous blood, is blackish purple. Viewed by spectrum analysis, the hemoglobin of arterial blood differs from that of venous blood, the former being combined with oxygen and the latter being deoxidized.
Blood has a saline and disagreeable taste, and, when fresh, a peculiar smell. It has an alkaline reaction. It is not, as it appears, homogeneous, but under a powerful microscope is seen to be a colorless fluid with little, round red bodies called blood disks or blood corpuscles, and a few larger ones called white corpuscles floating about in it. When removed from the body and allowed to stagnate it separates into a thicker portion called cruor, crassamentum or clot, and a thin ner one denominated serum. See BLEED ING, BLOOD LETTING, etc.
In law, whole blood is descent not simply from the same ancestor, but from the same pair of ancestors, while half blood is descent only from the one. The corruption of blood is the judicial strip ping it of the right to carry with it up or down the advantage of inheritance; its purification or restitution is the restora tion to it of the privilege of inheritance.