Rensselaer Semi-Weekly Republican, Volume 37, Number 28, Rensselaer, Jasper County, 11 April 1905 — BONE STRUCTURE. [ARTICLE]

BONE STRUCTURE.

V r - The Compact hiid the Spongy Kind and Their Strength. Bone is of two kinds, compact and spongy. As the result of careful experiments it has been shown that compact bone is twice os strong as oak, considered simply as building material. In the shaft of a long bone It Is In reality much stronger than this, for It Is arranged on the advantageous principle of the hollow pillar, which gives the fullest resisting power with the least possible expenditure of substance The delicate layers and bars of spongy bone are arranged on the principle of an arch, enabling very considerable pressures to be resisted. It was found that a cubic inch of this tissue taken from the lower end of the thigh bone and weighing only fifty-four grains was quite uninjured by a dead weight of 448 pounds. The curved bones which roof in theskull are 'constructed to resist great pressure, while they check the transmission of shocks to the brain. Arranged in the form of a dome, they consist of compact bones, with a spongy layer between. These are known as “tables” of the skull. The outer and inner tables are immensely strong, while the middle table serves as a buffer by which the force of blows is distributed.