In a previously published article, I1 reported the results of experiments which I had performed to determine the effect of variations in the blood phosphorus on the rate of calcification of callus in fractures. These experiments were made on the basis of reactions in vitro and with recent work on rickets as a background; and they were entirely negative. Continued interesting reports on experimental rickets have stimulated the present attempt to accelerate the calcification of fracture callus through the application of the factors that will influence the calcification of bone in that condition.
Workers on the vitamins lay stress on the fact that no good is to be expected from any superabundance of these substances in the dietary intake. Deficiency alone is of significance. In the presence of conditions brought on by deficiency, an addition to the diet of the particular vitamin concerned will result in a return to