Composition of bones has been made with collagen and other molecules. Organic or animal matter, about i/3,consisting of gelatin, vessels and fat. Inorganic, or mineral, about consisting of phosphate and carbonate of calcium (621^ per cent.), with fluoride of calcium, phosphates of magnesium, sodium, and chloride of sodium (4/1 percent.).
Heat will remove the organic matter and leave the inorganic;dilute Nitric or Hydrochloric acid will remove the inorganic, and leave the organic. In old age the inorganic constituents predominate, and the bones are brittle ; in youth the organic predominate, and epiphany dislocation is more common than fracture, especially in the long bones of the extremities.