In the course of an earlier investigation1 it was noted that a healing infected fracture showed a much lower level of phosphatase activity than did a sterile one of the same age. This suggested that retarded or suspended healing of infected fractures may be the result of diminished phosphatase activity. The literature concerning the relation between fractures and phosphatase activity in blood and bone has been reviewed previously.1 It has been pointed out by Roe and Whitmore2 in a clinical study of phosphatase activity in chronic infections of bone that there was no uniform rise in the phosphatase content of the blood.
Bilateral osteotomy with block resection of 1 cm. of the shaft was done on the radiuses of adult rabbits, and at the same time blood was removed from the heart for initial determinations of the level of phosphatase. The osteotomy wound on one side