The response of the body to extensive hemorrhage is an indication of the protective mechanisms that are at its disposal and the way in which they may be adapted to its use in such emergencies. Loss of blood is not to be identified simply with depletion of fluid; otherwise it could be readily replaced by ingestion of water. The plasma and cells of the blood have special chemical components that characterize them. It has been stated recently that the inorganic composition of plasma differs so widely from that of corpuscles that analyses of whole blood without reference to cell composition and the relative proportion of cells and serum are of little significance.
After severe hemorrhage, as Kerr 1 has pointed out, the organism employs every possible means to secure normal nutrition of the tissues by restoring blood volume. The dependence of a normal blood flow on the restoration of blood