Blood specific gravity studies

Abstract 1.1. The average specific gravity of normal human erythrocytes is 1.0971. This factor is fairly constant in different persons, but in anemia there frequently is a greater departure from the average than in normals. 2.2. The hematocrit may be calculated from the specific gravity of whole blood and of plasma in human beings. Also a fairly accurate estimate of red blood cell count, hemoglobin, and hematocrit may be made from the specific gravity of whole blood alone, since these values bear a constant relationship to one another. 3.3. Specific gravity of whole blood, hemoglobin concentration, hematocrit, and red blood cell count are uniformly efficacious as indicators of hemoconcentration and relative blood volume change. 4.4. Protein concentration or specific gravity of plasma is not a satisfactory indicator of hemoconcentration during the course of shock, since protein is lost from the circulating blood.