To the ultimate explanation of the phenomena with which he dealt he contributed nothing, and it is noteworthy in this connexion that if he did not maintain to the end of his life the corpuscular theory he never explicitly adopted the undulatory theory of light.
The pioneer work in this field, now frequently denominated " spectro-chemistry," was done by Sir Isaac Newton, who, from theoretical considerations based on his corpuscular theory of light, determined the function (n 2 - 1), where n is the refractive index, to be the expression for the refractive power; dividing this expression by the density (d), he obtained (n 2 - i)/d, which he named the " absolute refractive power."
The theoretical basis upon which this formula was devised (the corpuscular theory) was shattered early in the 19th century, and in its place there arose the modern wave theory which theoretically invalidates Newton's formula.
On light Franklin wrote to David Rittenhouse in June 1784; the sum of his own conjectures was that the corpuscular theory of Newton was wrong, and that light was due to the vibration of an elastic aether.
The mean corpuscular volume (MCV) will be measured to compare the size of RBCs with normal RBCs.