ferric oxide, which led to many of the ideas expressed here, was supported by the United States Atomic Energy Commission under Contract No. nT(30-1)-956. The authors wish to acknowledge
Mr. S. Uchida for performing some of the potentiometric titrations on Fez03. The interest shown and the valuable comments made by Dr. J. Th. G. Overbeek also are gratefully acknowledged.
THE SOLUBILITY BEHAVIOR OF HYDROXYLSPATITE BY VICTORI
