CIRCULATION. 127 



form the operation of restoration on the other parts, therefore they 

 themselves mnst first be perfect. They would seem to have more of 

 the Polypus in them than any other part of the body. This is, perhaps, 

 more in the absorbents than in the arteries or veins, for we can conceive 

 a part injured by accident, and, as it were, standing still for a little 

 while ; but we see iilceration going on very rapidly, which proves an 

 immediate formation of vessels for absorption. 



The first two, viz. the arteries and the veins, belong immediately to 

 the motion of the blood, or the Circulation. The arteries carry the 

 fluid from the general reservoir, the heart, to all the different parts of 

 the body, and the veins bring it back again. 



Of the Arteries. 



The arteries, which carry the fluid to all the parts of the body, con- 

 stantly dispose of part of that fluid in the different operations of the 

 body, according to their different affections ; adding to the whole while 

 growth is necessary, making up losses where the old is either improper 

 or destroyed, and throwing out of the direct line of their motion parts of 

 that fluid, which, according to the various affections and actions of these 

 arteries, become considerably altered in this passage, called secretions. 



The juices so secreted are intended for various purposes in the ma- 

 chine : some for stimulants, as the bile ; some for mechanical purposes, 

 as the tears, synovia, saliva, &e. ; some for a store of nourishment, as 

 the fat ; while others are thrown out of the body as useless, because 

 they have already performed all their purposes, as the urine, &c. 



Of the Veins. 



The other set of tubes — the veins — were considered as less active, 

 being principally employed in bringing the red part of the blood back, 

 after it had lost its most salutary parts, or performed those ofiices, 

 whatever they are, for which it was sent out. 



This act of carrying back the red blood was not considered as the 

 only office of the veins ;_ many of their beginnings were not only 

 supposed to arise from the terminations of arteries, but were also sup- 

 posed to arise from most, if not all, the surfaces of the body, both in- 

 ternal and external, making so many inlets into the general system, 

 bringing in matter into the common mass of fluids for the support of the 

 whole ; and also to bring back many of the parts which were by the 

 arteries secreted from the blood for the different purposes of life, such 

 as the synovia and lubricating fluids of all kinds ; which fluids having 

 answered their different purposes, and having become unfit for any 



