Circulation of the Blood 141 



taneously, as in those who have died from drowning 

 or syncope, or who die suddenly, you will find the 

 arteries, as well as the veins, full of blood. 



3d. With reference to the third point, or that of the 

 spirits, it may be said that, as it is still a question what 

 they are, how extant in the body, of what consistency, 

 whether separate and distinct from the blood and solids, 

 or mingled with these, upon each and all of these 

 points there are so many and such conflicting opinions, 

 that it is not wonderful that the spirits, whose nature 

 is thus left so wholly ambiguous, should serve as the 

 common subterfuge of 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 un- 

 ravelling the plot, and bringing about the catastrophe. 



Fernelius, and many others, suppose that there are 

 aereal spirits and invisible 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 physicians 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. Farther, besides the 

 three orders of influxive spirits adverted to, a like 

 number of implanted or stationary spirits seem to be 

 acknowledged ; but we have found none of all these 

 spirits by dissection, neither in the veins, nerves, 



