126 ARTERIES AND VEINS ; THEIR [BOOK I. 



great contractile powers : they are large near the 

 heart, but soon branch out of a lesser size, until, 

 entering the smaller organization of the solids, they 

 become very minute, infinitely numerous and more 

 sensitive, thus affording the means of renovation, or 

 growing, to the flesh, bones, skin, hair, hoofs, &c. 

 The large artery communicates with minor branches, 

 soon after leaving the heart, by two rows of open- 

 ings, like perforations , in its lower side, at two or 

 three inches asunder. Some one has likened the 

 arrangement of these vessels to the stem, branches, 

 and twigs of a currant-bush , and so might the veins 

 that run nearly parallel to the arteries, through 

 every part of the animal, but are so constructed 

 and arranged, as to take up and reconvey the 

 blood (which the arteries constantly deposit) back 

 again to the heart ; and the similarity will still 

 further hold good, if we extend it to the leaves of 

 the bushy and compare these to the glands (see 

 sections 27, 28.), in every one of which an artery 

 terminates, and deposits its nutritious contents, and 

 where every small vein begins the absorption of 

 what the artery had so left behind. This absorp- 

 tion, when obstructed, lax, or otherwise imperfect 

 on the surface, may be restored by stimulating the 

 parts with spirits ; when it is too high, and labour- 

 ing greatly in consequence of the viscidity of the 

 blood, local inflammation is engendered, and one or 

 other of those diseases we shall hereafter treat 

 under " abscess," is the consequence of this con- 

 stitutional derangement. Blood that is thick, heavy, 



