CHAPTER FIRST. 



THE FRAMEWORK OF THE SYSTEM. — OSTEOLOGY, OR 

 A DESCRIPTION OF THE BONES. 



DEFINITIONS AND DESCRIPTIONS. 



80. Chemical Composition of Bone. — The Bones of all 

 vertebrate animals are principally composed of the Phosphate 

 and Carbonate of Lime, and, with the exception of the Teeth 

 and articular extremities, are closely covered by a firm mem- 

 brane called the Periosteum. By chemical analysis the com- 

 position is as follows : 



Organic substance (Osteine or Cartilage) 33.00 



Phosphate of Lime 57.00 



Carbonate of Lime , 8.00 



Fluorid of Calcium 1.00 



Phosphate of Magnesia 1.00 



100.00 



81. Cartilage and Salts of Lime shown. — Hence we see 

 that the principal constituents of bone are the salts of Lime 

 and Cartilage. The former can be easily obtained by burning 

 the bone a while in a hot fire, which appears like a white 

 powder when crushed. The Cartilage is obtained by im- 

 mersing it for a considerable time in a dilute acid, when we 

 have the form of the bone perfectly retained, although nothing 

 is left but cartilage. Its elastic character may be inferred 



80. What are the principal ingredients of bones? Where is the Periosteum found? 

 Give the chemical analysis. 81. How can the earthy ingredients be shown? The car- 

 tilage? 



