CHAPTER II 

 THE FRAMEWORK OF THE BODY 



31. The Bony Framework. The framework on which 

 the body is built consists chiefly of a large number of 

 bones, called the skeleton. There are in the adult human 

 body about two hundred distinct bones. The teeth are 

 not bones, but are a part of the structure of the skin. 



The bones of the body give firmness, strength, and 

 protection to the soft tissues and vital organs. They 

 also form levers for the muscles to act upon, and thus 

 render possible many complicated movements. 

 * 32, Chemical Composition of Bone. Bone is composed 

 of earthy, or mineral matter (chiefly in the form of lime 

 salts), and of animal matter (principally gelatin), in the 

 proportion of two-thirds of the former to one-third of the 

 latter. The proportion of earthy to animal matter varies 

 with age. In infancy the bones are composed more largely 

 of animal matter and are more easily deformed than in 

 later life. Hence an infant's bones are not easily broken. 

 In childhood the bones still contain a larger percentage of 



The Study of the Skeleton in the Schoolroom. A human 

 skeleton is almost a necessity in the study of bones and their 

 action. To this intent, schools of a higher grade should be 

 provided either with a mounted skeleton or with the separate 

 bones. Oftentimes a loan of a complete skeleton or many of 

 the bones can be secured of some medical man in the vicinity. 

 In fact, there is no other way to study properly the structure 

 and use of the bones and joints than by the bones themselves. 



