Abstract
1. Some physical properties of living and dead bone have been studied in rats; most of these are interrelated and ultimately depend upon the composition of the tissue.
2. Dead bone, remaining within the body, does not take up measurable amounts of mineral from the tissue fluid but retains its original physical properties of radiographic density, specific gravity, strength and composition.
3. The altered radiographic density of avascular bone seen in clinical practice is almost certainly relative unless there has been concomitant appositional new bone formation.
4. Some other explanation must be sought for the finding that dead bone takes up significant amounts of bone-seeking isotopes in radioactive tracer studies.