Circulation of the Blood 139 



tionably, upon the subsidence of this fermentation, the 

 blood would return to its original quantity of a few 

 drops j (and this, indeed, is the reason that some assign 

 for the usually empty state of the arteries in the dead 

 body ;) and so should it be with the arterial blood in 

 the cup, for so it is with boiling milk and honey when 

 they come to cool. But if in either basin you find 

 blood nearly of the same colour, not of very different 

 consistency in the coagulated state, forcing out serum 

 in the same manner, and filling the cups to the same 

 height when cold that it did when hot, this will be 

 enough for any one to rest his faith upon, and afford 

 argument enough, I think, for rejecting the dreams that 

 have been promulgated on the subject. Sense and 

 reason alike assure us that the blood contained in the 

 left ventricle is not of a different nature from that in 

 the right. And then, when we see that the mouth of 

 the pulmonary artery is of the same size as the aorta, 

 and in other respects equal to that vessel, it were 

 imperative on us to affirm that the pulmonary artery 

 was distended by a single drop of spumous blood, as 

 well as the aorta, and so that the right as well as the 

 left side of the heart was filled with a brisk or fermenting, 

 blood. 



The particulars which especially dispose men's minds 

 to admit diversity in the arterial and venous blood are 

 three in number : one, because in arteriotomy the blood 

 that flows is of a more florid hue than that which 

 escapes from a vein ; a second, because in the dis- 

 section of dead bodies the left ventricle of the heart, 

 and the arteries in general, are mostly found empty ; a 

 third, because the arterial blood is believed to be more 

 spirituous, and being replete with spirit is made to 

 occupy a much larger space. The causes and reasons, 

 however, wherefore all these things are so, present 

 themselves to us when we ask after them. 



i st. With reference to the colour it is to be observed, 

 that wherever the blood issues by a very small orifice, 



