HOW TO KNOW HIM. 21 



And, first, because it is the home of the heart. The 

 heart, please remember, is the centre of the entire blood- 

 system of the body. By the blood which it circulates 

 alone can the structure be nourished and sustained in 

 vigor and health day by day. By it, also, alone can the 

 effete substance which is constantly accumulating in the 

 system, as the result of every motion the animal makes, 

 be collected, and discharged from the system. It is to 

 the heart, therefore, you see, that we are indebted for 

 whatever needed element is added to the system, and 

 whatever unneeded and harmful element is removed 

 therefrom. Heart-health means muscular health, bone 

 health, universal health. Heart-disease means weakness 

 of the muscles, unreliable bone substance, and a more or 

 less impairment of the entire system. Whatever con- 

 cerns the heart, therefore, and whatever affects it, direct- 

 ly or indirectly, for good or ill, is worthy of the closest 

 attention. Especially the chest, — in which the heart is 

 lodged, by which it is protected, and which either 

 cramps it, or allows it the needed liberty of action, — 

 as it is properly or improperly formed, challenges our 

 inspection. 



In the second place, the reason why the chest of the 

 horse is worthy of the horseman's most careful study 

 is because it is the cavity in which Nature has located 

 the lungs. I shall, in another portion of this work, 

 treat more fully of the use and condition of the lungs. 

 But this much I will observe at this point : the blood 

 which is circulated by the heart can be vitalized and 



