476 HIPPOCRATES. 



fluids, whether impure air, bad diet, want of 

 rest, fatigue, retention of the excretions, or the 

 depressing passions of the mind, deranges the 

 healthy condition of the whole system ; that in- 

 flammation or fever is an effort of nature, or 

 the Qvms to expel morbific matter from the hu- 

 mours ; and that the highest wisdom of the phy- 

 sician is to follow the proceedings of nature in 

 practice : above all, to preserve and restore the 

 healthy condition of the blood by nutritious 

 food, pure air, exercise, &c. ; to moderate its mo- 

 tions when excessive, and increase them when 

 languid ; to open the bowels, skin, and other 



it, conveyed from the trachea to the heart, and thence to all parts 

 of the body by the arteries, which they called pneumatic vessels ; 

 and that the fuliginous portion of the air was thrown off from 

 the lungs by expiration. He further states, that all the Greeks, 

 from Hippocrates down to his own time, believed that after 

 food was dissolved in the stomach, it was conveyed to the 

 intestines, and thence to the liver, where it was converted into 

 blood, prepared for nutrition, and then conveyed to the vena 

 cava, to be distributed to all parts of the system ; he further 

 taught that the office of respiration was to cool the blood. (De 

 Usu Partium, lib. iv.) It was not until the time of Herophilus and 

 Erasistratus, that the brain and nervous system were fully recog- 

 nized as the organ of sensation, perception, and voluntary motion. 

 Nor was it until the middle of the sixteenth century, that Ser- 

 vetus distinguished the pulmonary circulation from that of the 

 general system ; or, that the lungs were discovered to be the 

 organ of sanguification. It is therefore clear, that the know- 

 ledge of the Greeks in regard to the specific office of the lungs, 

 heart, liver, blood vessels, and nerves, was not only vague and 

 imperfect, but fundamentally erroneous. 



