10 PRELIMINARY REMARKS. 



The adipose membrane is the same as the cellular, but the former 

 is rendered impervious by the distension its contents occasion. 



Vessels are tubes, composed of different membranes, the strata 

 of which are termed tunica, or coats : they are named according to 

 the fluids they contain, as blood-vessels, vasa lactea, lymphatics, 

 &c. The smallest extremities of all vessels are generally termed 

 capillaries. The blood-vessels are of two kinds ; arteries, which 

 carry the blood from the heart to every part of the system ; and 

 veins, which bring it back again to the heart. The arteries are thicker 

 and deeper seated than the veins ; the veins have valves which 

 open towards the heart at different distances to prevent the blood 

 from returning, but are not irritable like arteries, except the large 

 ones near the heart. 



By nerves are meant the white ropy parts or cords, which pro- 

 ceed from the brain and spinal marrow, and are spread over all the 

 parts of the body, by small ramifications. They are the seat and 

 origin of all our faculties, of sensation and motion. 



The muscle is what we commonly call flesh, which is composed 

 of various distinct portions : its white ends are termed tendon. 



Glands are clustered bodies distinguished from other parts by 

 their form, consistence, texture, connexion. 



The kidneys, and the pancreas or sweetbread, are properly de- 

 nominated glands. 



Fat and marrow is that oily substance composed partly of cel- 

 lular, partly of membraneous, and partly of an unctuous matter ; 

 it is entirely deprived of sensibility, like all liquors secerned from 

 the blood. Marrow differs only by its fineness, and from its being 

 situated within the bones. 



By viscera, is meant all the internal parts contained in the cavity 

 of the body. Every part capable of any function is termed an 

 organ. 



In this work all the leading divisions will be the subject of a 

 particular chapter. 



