SOME NEW VIEW POINTS IN NUTRITION 405 



ignorance. Persons of limited information, when they are at a loss to assign 

 a cause for anything, very commonly reply that it is done by the spirits; and 

 so they bring the spirits into play upon all occasions; even as indifferent poets 

 are always thrusting the gods upon the stage as a means of unraveling the 

 plot, and bringing about the catastrophe. 



Fernelius, and many others, suppose that there are aerial spirits and in- 

 visible substances. Fernelius proves that there are animal spirits, by saying 

 that the cells in the brain are apparently unoccupied, and as nature abhors a 

 vacuum, he concludes that in the living body they are filled with spirits, just 

 as Erasistratus had held that, because the arteries were empty of blood, there- 

 fore they must be filled with spirits. But medical schools admit three kinds 

 of spirits: the natural spirits flowing through the veins, the vital spirits 

 through the arteries, and the animal spirits through the nerves; whence physi- 

 cians say, out of Galen, that sometimes the parts of the brain are oppressed by 

 sympathy, because the faculty with the essence, i. e., the spirit, is overwhelmed ; 

 and sometimes this happens independently of the essence. Further, besides the 

 three orders of influxive spirits adverted to a like number of implanted or sta- 

 tionary spirits seem to be acknowledged; but we have found none of all these 

 spirits by dissection, neither in the veins, nerves, arteries, nor other parts of 

 living animals. 11 



Here we have the point of view of the true investigator, the true 

 scientific spirit. Abide by the facts and base your reasoning upon 

 careful observation. Although Harvey lived at a period when physi- 

 ological knowledge, as we understand it to-day, was almost wholly 

 unknown, and when the influence of the " spirits " dominated all 

 thought, yet he applied rational methods of scientific study and drew 

 logical conclusions from his observations, with the result that to him 

 belongs the honor of discovering the motion of the heart and the 

 circulation of the blood. What he could not see he had no faith in, 

 and so the theories concerning the spirits of the body he laid aside 

 as having no foundation in fact. Would that to all of us might be 

 given that same true appreciation of the importance of scientific obser- 

 vation upon which depends the advance of exact knowledge. 



"Quoted from William Harvey: "An Anatomical Disquisition on the 

 Motion of the Heart and Blood in Animals," translated from the Latin by 

 Robert Willis. Everyman's Library, London and New York. 



