The principles and practice of dentistry : including anatomy, physiology, pathology, therapeutics, dental surgery and mechanism / by Chapin A. Harris.

  • Harris, Chapin A. (Chapin Aaron), 1806-1860.
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: The principles and practice of dentistry : including anatomy, physiology, pathology, therapeutics, dental surgery and mechanism / by Chapin A. Harris. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    55/854 (page 47)
    CHAPTER III. OSTEOLOGY. T) ONE is one of the hardest substances in the body. It is composed JJ of animal or organic matter in intimate association with earthy, or inorganic matter. From the organic matter the bone derives the properties of toughness and elasticity; and from the earthy material, hardness and solidity. The mineral matter may be dissolved out by a dilute solution of nitric or muriatic acids, whilst the animal matter remains unaffected, retaining its form, though loosing its hardness, so that the long bones, so great is their flexibility, may be tied into a knot; on the other hand, by subjecting them to a high heat in an open fire, Avhilst exposed to the air, the animal matter may be consumed, leaving the mineral to preserve the form of the bone, but so insecurely that it will crumble to ashes in the grasp of the hand. The composition of bone, according to Berzelius, is about one-third animal and two-thirds mineral matter: Animal Matter, Gelatin and Bloodvessels, . . . . 33-30 ] Phosphate of Lime,. ..... 51-04 Inorganic I Carbonate of Lime, ..... 11-30 or [ Fluoride of Calcium, ..... 200 Earthy Matter. Phosphate of Magnesia, . . . . 116 Soda and Chloride of Sodium, . . . 1-20 The proportion of earthy and animal matter is generally thought to vary with varying age. According to Shreger, this difference is as follows: CHILD. ADULT. OLD AGE Animal Matter, . . 47-20 20-18 12-2 Earthy Matter, 48-48 . . 74-84 . . 84-1 To this supposed difference has commonly been ascribed the greater brittleuess of bones in aged people; but recent analyses tend to show that bone is at all periods of individual life chemically the same, and if so, the inference growing out of the error of former analyses is false- The development of bone takes place in a manner somewhat differ- ent from that of most other tissues, since we have, in addition to the germinal matter and formed material, a deposit of earthy matter in the latter. The formation of the animal matter is avital phenomenon, the deposit of earthy matter a purely physical one. The cell or elementary part of bone consists of a soft central