184 THE HUMAN HEART. 



standing just ^beyond the range of every conception that has en- 

 tered the w 

 childhood : 



tered the world, and beckoning us forwards in words familiar from 



" There are more things in heaven and earth, Horatio, 

 Than are dreamt of in your philosophy ;" 



and then as we pitter out, " 'Tis strange, 'tis wondrous strange," 



the same apostle to the Saxons speaks yet again in mother English : 



" And therefore as a stranger give it welcome." 



There are points in the structure of the heart of which we have 

 said nothing hitherto, but we must now describe what are called the 

 coronary vessels, which are supposed to nourish the heart with blood. 

 They are called coronary from corona, a crown, because they run in 

 crowns or coronal circles around the heart. They arise from the 

 aorta close beside the semilunar valves, and running around the 

 base of the heart, and sending branches down the lines of partition 

 between its fourfold chambers, they form a kind of vascular cage- 

 work in which it is contained. The coronary veins, said to begin 

 from the minutest twigs of the coronary arteries, by their consider- 

 able branches for the most part accompany those of the arteries, 

 and discharge themselves by one, two, or three orifices into the right 

 auricle. 



The interior of the four cavities of the heart is not a smooth even 

 surface, but is rendered extremely irregular by muscular columns, 

 projections and partitions; it is scooped, channeled, and caverned; 

 besides which, on the walls of the cavities there are minute open- 

 ings, the foramina of Thebesius, which are supposed to be the 

 mouths of little veins. 



Everything in nature, and especially the cardinal movements of 

 living systems, are designed for more than one use; for, unlike 

 rest, motion is a steed which can have innumerable riders. We 

 are, therefore, certain that the movements of the heart are of other 

 uses besides the propulsion of the general blood, unless it could be 

 shown that the provisions of the heart are exhausted in this pro- 

 pulsion ; which cannot be done. On looking further at the heart 

 itself, we find that its working is also employed to insure the 

 commixture of the elements of the blood, especially in the right 



