376 THE POPULAR SCIENCE MONTHLY. 



circumstances spontaneously furnished by Nature ; in the other, we 

 obtain it from experiment, which possesses the great advantage over 

 observation not only of furnishing us with a much greater number of 

 variations than is to be found naturally presented, but also of enabling 

 us to produce the precise form of combination or variation which is 

 needed for our purpose. 



Harvey, in a true sense, adopted the Baconian system of interrogat- 

 ing Nature by appeal to observation and experiment, and drawing 

 conclusions out of the facts presented, and yet it is evident that the 

 " Novum Organum " was not published till after the discovery of the 

 circulation was made. Bacon's new method of conducting research 

 and discovering the truths of Nature was placed before the public in 

 1620. Harvey's work on the circulation, "Exercitatio Anatomica de 

 Motu Cordis et. Sanguinis Animalibus," was not published till 1G28, but 

 it has been generally allowed that his discovery was made known in 

 his first course of Lumleian lectures, delivered at the college in 1616 ; 

 and, thanks to the meritorious labors of a committee of the college, 

 this has now been rendered open to verification by the very interesting 

 volume just prepared, and on the point of being issued, containing a 

 reproduction in autotype form of his original lecture-notes in his own 

 handwriting. Harvey, then, must have been thoroughly in the van of 

 progress taking place in his day ; and, further, the contemporaries of 

 Bacon must have been acquainted with the new system of philosophy 

 before the " Novum Organum " was published. 



Harvey's discovery established a new departure in physiology. 

 Without a knowledge of the circulation, nothing really could be 

 known about the various operations taking place within us. It is hard, 

 with the knowledge now possessed, to realize 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 recog- 

 nized, but it was taught that the blood went to the lungs for their nu- 

 trition, and " to be elaborated and subtilized 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 whence the body 

 was supplied with blood through the veins, in which there was be- 

 lieved to be a to-and-fro current, a flux and reflux, that was compared 

 to the ebb and flow of the tide in the classic straits of Euripus. Truly, 

 indeed, may it be asserted, that our ancestors stand in the twofold 

 position of our parents with respect to age, our children with respect 

 to knowledge. 



It was not without opposition that Harvey's views were received ; 

 and the high position in his profession he had attained did not suffice 

 to prevent his escape from the effect of the prejudice against innova- 

 tion entertained by the multitude. Aubrey tells us he had " heard 

 him say that after his book on the circulation of the blood came out, 



