390 ON GENERATION. 



through the fluid ; in the same way, as the mucus in question 

 rendered recrudescent by corruption, liquefies and returns to 

 the state of sanies. 



So far at this time have I thought fit to produce these my 

 own observations on this constituent of the blood, intending to 

 speak more fully of it as well as of the other constituents cog- 

 nizable by the senses, and admitted by Aristotle and the medical 

 writers. 



That I may not seem to wander too widely from my purpose, 

 I would here have it understood that with Aristotle I receive 

 the blood as a part of the living animal body, and not as it is 

 commonly regarded in the light of mere gore. The Stagirite 

 says : l " The blood is warm, in the sense in which we should 

 understand warm water, did we designate that fluid by a simple 

 name, not viewing it as heated. For heat belongs to its 

 nature ; just as whiteness is in the nature of a white man. But 

 when the blood becomes hot through any affection or passion, 

 it is not then hot of itself. The same thing must be said in 

 regard to the qualities of dryness and moistness. Wherefore, 

 in the nature of such things they are partly hot and partly 

 moist ; but separated, they congeal and become cold ; and such 

 is the blood." 



The blood consequently, as it is a living element of the body, 

 is of a doubtful nature, and falls to be considered under two 

 points of view. Materially and per se it is called nourishment ; 

 but formally and in so far as it is endowed with heat and spirits, 

 the immediate instruments of the vital principle, and even with 

 vitality (anima), it is to be regarded as the familiar divinity 

 and preserver of the body, as the generative first engendered 

 and very principal part. And as the prolific egg contains 

 within it the matter, instrument, and framer of the future 

 pullet, and all physicians admit a mixture of the seminal fluids 

 of the two sexes in the uterus during or immediately after in- 

 tercourse as constituting the mixed cause, both material and 

 efficient, of the foetus ; so might one with more propriety main- 

 tain that the blood was both the matter and preserver of the 

 body, though not the sole aliment ; because it is observed that 

 in animals which die of hunger, and in men who perish of 



1 De Part. Anim. lib. ii, cap. 3. 



