* 142 LETTERS TO BROTHER JOHN. 



become aware of the presence of the chyle, which 

 is stimulating them to action. They answer the 

 call, by erecting themselves; protruding themselves 

 forward ; dipping, as it were, their mouths into the 

 chyle ; and then retracting and closing them, they 

 thus perform an actual suction (if you will allow 

 the term), by which the chyle is drawn within the 

 caliber of these beautiful little vessels. 



The chyle, thus absorbed, travels along the 

 lacteals (that is, the chylous absorbents); is nitrated 

 through their glands ; is emptied into the thoracic 

 duct ; and, by it, is poured into the blood of the veins 

 about the bottom of the neck, and is carried by the 

 current of the blood through the right side of the 

 heart, along the pulmonary artery, into the lungs. 



While the chyle is traversing the chylous absor- 

 bents and their glands, it undergoes a change, 

 the nature of which is not understood ; but it is a 

 change which advances it another degree nearer to 

 the nature of blood. By the time, therefore, that 

 your dinner or, rather, that which was once the 

 food which constituted your dinner has reached 

 your lungs, it has become almost blood: but it 

 has not yet become quite blood. 



When the chyle has reached the lungs, it is then 

 exposed to the action of the air which we inhale, 



