28 



his day ; and, further, the contemporaries of Bacon 

 must have been acquainted with the new system of 

 philosophy before the " Novum Organum " was 

 pubhshed. 



Harvey's discovery established a new departure 

 in physiology. Without a knowledge of the circu- 

 lation nothing really could be known about the 

 various operations taking place within us. It is 

 hard, with the knowledge now possessed, to realise 

 the state existing at the time the circulation was 

 discovered. The passage of blood from the right 

 to the left side of the heart had, it is true, already 

 been recognised, but it was taught that the blood 

 went to the lungs for their nutrition, and " to be 

 elaborated and subtilised by the reception of a 

 spirit from the air in inspiration and the exhalation 

 of a fuliginous matter in expiration." The heart 

 and arteries were supposed to be the seat of the 

 vital spirit, and the liver to be the fountain from 

 whence the body was supplied with blood through 

 the veins, in which there was believed to be a 

 to-and-fro current — a flux and reflux, that was 

 compared to the ebb and flow of the tide in the 



