An increase in the mean corpuscular hemoglobin concentration is also consistent with hereditary spherocytosis. The size is reflected in the mean corpuscular volume (MCV). The corpuscular theory was largely developed by Isaac Newton. Newton's corpuscular theory of light was gradually succeeded by the wave theory. A low mean corpuscular volume also appears during the course of body iron depletion. Its success favoured the wave theory of light over the previous corpuscular theory. His answer to the universal attraction in corpuscular physics models was universal elasticity. In the 17th century, Sir Isaac Newton described light through a corpuscular theory. In 1704, Newton published "Opticks", in which he expounded his corpuscular theory of light. Then came unsuccessful attempts to combine gravity and either wave or corpuscular theories of gravity. Newton in his "Opticks" of 1704 proposed instead a corpuscular theory of light. The mean corpuscular volume is a part of a standard complete blood count. Reticulocytes are also relatively large, a characteristic that is described by the mean corpuscular volume. Arago tried to explain his observations in "corpuscular" terms. Corpuscular optics was becoming expensive on assumptions.