The chemical study on bone and cartilage to be reported here supplements the work described in an earlier paper1 on the mineral composition of the human fetus. In other investigations2 made on similar material only a few of the mineral constituents have been considered. Apparently the percentage of some minerals remains fairly constant during short periods of fetal growth, but it has not been shown that this constancy persists for the entire fetal period or that the concentrations of other mineral elements show the same tendency. This investigation presents the values for the most important mineral constituents of specimens of bone and cartilage taken from twenty-one fetuses weighing from 197 to 4,150 Gm.
The material for this study was obtained at autopsy from eight to sixteen hours after death. Postmortem changes during the interval between death and autopsy were controlled as far as possible by refrigeration. The specimens