10 STUDIES IN ADVANCED PHYSIOLOGY. 



doubted the truth of the conceptions of Praxagoras regard- 

 ing the arteries. They were in all calculations supposed to 

 to carry air or spuitus. This spirit us or pncuma they 

 made the subject of many fanciful theories. It was still 

 believed to be taken in by the breath and then carried to 

 the heart, to be distributed by the arteries. It was the 

 principle of life, and we have the ancient belief still illus- 

 trated in the familiar expression "the breath of life." 



This spiritus by its vital energy caused the arteries to 

 pulsate. Brasistratus carried this notion so far as to rec- 

 ognize two kinds of spiritus. One which was taken from 

 the air is carried in the arteries and left side of heart, and 

 the other a higher spiritus made from the first by the brain 

 and stored in the ventricles of the brain (whence their 

 use) , from there to be distributed over the body by the 

 nerves giving feeling and volition, while the part that 

 remained in the brain became the bearer of consciousness 

 and individuality. This was called the "psyche," a name 

 retained to this day in such terms as psychical, psychology, 

 etc., while we still speak of animal spirits, and sometimes 

 hear of the nerves containing nervous flttid. Fever was 

 believed to be due to the filling of the large arteries with 

 blood and so interfering with the movements of the pneuma, 

 while inflammation resulted when the blood was driven by 

 the pneuma to the ends of the arteries, whence their dis- 

 tension. In a wound the artery contained blood, because 

 as the air, or pneuma, leaked out and so caused a vacuum, 

 blood soaked in to take its place. Normally blood was 

 contained in veins only. 



GALEN. 



The physiology of the ancients reached its culminating 

 point in the learned Galen, who practiced medicine in the 

 city of Rome when the Eternal City had reached the zenith 

 of its importance. He was a Grecian by birth and no doubt 

 belonged to that class of Greeks which had been called to 

 Rome to superintend the instruction of the imperial city. 



