I2O Circulation of the Blood 



In that paragraph especially where he describes the 

 circulation in the brain, he says : " And the brain by 

 means of the circulation sends back blood to the heart,, 

 and thus refrigerates the organ." And in the same 

 way are all the more remote parts said to refrigerate 

 the heart ; thus in fevers, when the praecordia are 

 scorched and burn with febrile heat, patients baring 

 their limbs and casting off the bedclothes, seek to cool 

 their heart ; and the blood generally, tempered and 

 cooled down, as our learned author states it to be with 

 reference to the brain in particular, returns by the 

 veins and refrigerates the heart. Our author, therefore, 

 appears to insinuate a certain necessity for a circulation 

 from every part, as well as from the brain, in opposition 

 to what he had before said in very precise terms. But 

 then he cautiously and ambiguously asserts, that the 

 blood does not return from the parts composing the 

 second and third regions, unless, as he says, it is drawn 

 by force, and through a signal deficiency of blood in 

 the larger vessels, &c., which is most true if these 

 words be rightly understood ; for by the larger vessels, 

 in which the deficiency is said to cause the reflux, I 

 think he must be held to mean the veins not the 

 arteries ; for the arteries are never emptied, save into 

 the veins or interstices of parts, but are incessantly 

 filled by the strokes of the heart ; but in the vena cava 

 and other returning channels, in which the blood glides 

 rapidly on, hastening to the heart, there would speedily 

 be a great deficiency of blood did not every part 

 incessantly restore the blood that is incessantly poured 

 into it. Add to this, that by the impulse of the 

 blood which is forced with each stroke into every 

 part of the second and third regions, that which is 

 contained in the pores or interstices is urged into the 

 smaller veins, from which it passes into larger vessels, 

 its motion assisted besides by the motion and pressure 

 of circumjacent parts ; for from every containing thing 

 compressed and constringed, contained matters are 



