ON GENERATION. 391 



marasmus, a considerable quantity of blood is still found after 

 death in the veins. And farther, in youthful subjects still 

 growing, and in aged individuals declining and falling away, 

 the relative quantity of blood continues the same, and is in the 

 ratio of the flesh that is present, as if the blood were a part of 

 the body, but not destined solely for its nourishment ; for if it 

 were so, no one would die of hunger so long as he had 

 any blood left in his veins, just as the lamp is not ex- 

 tinguished whilst there is a drop of inflammable oil left in 

 the cruise. 



Now when I maintain that the living principle resides pri- 

 marily and principally in the blood, I would not have it inferred 

 from thence that I hold all bloodletting in discredit, as dan- 

 gerous and injurious ; or that I believe with the vulgar that in 

 the same measure as blood is lost, is life abridged, because the 

 sacred writings tell us that the life is in the blood ; for daily 

 experience satisfies us that bloodletting has a most salutary 

 effect in many diseases, and is indeed the foremost among all 

 the general remedial means : vitiated states and plethora of the 

 blood, are causes of a whole host of diseases ; and the timely 

 evacuation of a certain quantity of the fluid frequently delivers 

 patients from, very dangerous diseases, and even from imminent 

 death. In the same measure as blood is detracted, therefore, 

 under certain circumstances, it may be said that life and health 

 are added. 



This indeed nature teaches, and physicians at all events pro- 

 pose to themselves to imitate nature ; for copious critical dis- 

 charges of blood from the nostrils, from hemorrhoids, and in 

 the shape of the menstrual flux, often deliver us from very serious 

 diseases. Young persons, therefore, who live fully and lead 

 indolent lives, unless between their eighteenth and twentieth 

 year they have a spontaneous hemorrhage from the nose or 

 lower parts of the body, or have a vein opened, by which they are 

 relieved of the load of blood that oppresses them, are apt to be 

 seized with fever or smallpox, or they suffer from headache and 

 other morbid symptoms of various degrees of severity and dan- 

 ger. Veterinary surgeons are in the habit of beginning the 

 treatment of almost all the diseases of cattle with blood- 

 letting. 



