DESCRIPTION. 83 



CHAPTER II. 



THE HUMAN LUNGS. 



Human life is illustrated by every organ of the body. Each 

 contributes a share to the general vitality. The brains are as the 

 tranquil inward respiring of existence elevated into mind; a life 

 which seems immaterial and motionless, until from the opened head 

 the capacities of organization come to light, and the brain demon- 

 strates that our noblest powers are incarnate, real and progressive. 

 That which is the secret of the brains is the open lesson of the 

 lungs. They live physically and largely the same life which the 

 brains live metaphysically and most minutely. In the running 

 wheel of life the imperceptible motion of the axle is thought; the 

 sweep at the periphery is respiration. The brains give us the free 

 principles of life, and the lungs, its free play in nature. 



It is this idea of the play of life which is the principal point in 

 our first knowledge of the lungs : it is in the completion of this 

 idea that we must endeavor to bring out their functions. Of all the 

 internal organs, not excepting the heart, the lungs move the most 

 evidently. And as they are the plainest engines in our frames, we 

 must, in that inevitable way from the known to the unknown, rea- 

 son perforce from them to other parts, which also are engines, 

 though more difficult to exhibit at work. 



The nose and mouth are the two doors which open inwards to- 

 wards the lungs ; the nose being the special entrance to the chest, 

 and the mouth, common to the chest and abdomen. The inner 

 door leading to the lungs is the fissure of the glottis, which opens 

 directly into the larynx, a cartilaginous box fitted up with muscles, 

 membranes, and other appliances requisite for the articulation of 

 sound. The larynx terminates in the windpipe or trachea, a pipe 

 extending from below the middle of the neck to opposite the third 



