INTERNAL ORGANS. 1 1 



indeed ; but from the right ventricle it is con- 

 veyed by the pulmonary artery to the lungs, 

 at the moment they are distended with air : here 

 the blood undergoes a wonderful alteration, it 

 resumes its bright scarlet colour, and is returned 

 by the pulmonary veins to the left side of the 

 heart, with all its original and essential quali- 

 ties restored to it. It is proper to observe, 

 that there are valves placed in such situations, 

 as effectually prevent the blood from taking a 

 retrosrrade course. Were it not for this con- 

 trivance, the blood would as readily be forced 

 into the left auricle as into the great artery^ when 

 the left 'ventricle^ which lies between them, con- 

 tracts, or shrinks up ; and so of the other parts. 

 Hence we may learn how important are the 

 functions of respiration and the circulation of 

 blood, how essential to the life of animals, and 

 bow dependent they are on each other. 



Viscera of the Abdomen. 



Having finished our description of the tho-. 

 racic viscera, we proceed to notice those of the 

 abdomeyi, or belly ; the first and most important 

 of which is the stomacL Whatever this orofan 



