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ANATOMY, PHYSIOLOGY, AND 

 MEDICINE. 



ANATOMY is understood to treat solely of the 

 structure of living beings, and Physiology 

 solely of their functions. 



The Skeleton. 



The skeleton of the human hody consists of 254 

 separate pieces of bone or osseous substances, most 

 of which contain a quantity of matter called marrow, 

 and are surrounded with a membrane called the pe- 

 riosteum. The height of the skeleton of a person 

 five feet eight inches high when alive, will generally 

 be found to be five feet seven inches. 



The skeleton of a middle-sized man weighs 13| 

 pounds, the usual weight of the brain is about 3|, 

 and that of the circulating blood 28 pounds. Total, 

 45 pounds, without muscles or intestines. 



Animals' bones are composed of lime and phos- 

 phoric acid (phosphate of lime). 



In the higher classes of animals, the bones are 

 generally interior ; but in the Crustacea and testacea, 

 (lobsters, oysters, &c.) they compose an external 

 case, within which all the soft parts are contained. 



The Embryon State. 



An embryo is usually about twenty inches in length ; 

 average weight about . 7 pounds, 

 ditto of twins . 1 1 



All quadrupeds, and mankind, in their embryon 

 state, are aquatics. 



