HYGIENE OF BREATHING. 121 



as it does in the case of these young men, whose health and 

 carriage are universally admired. 



Those persons who take constant exercise in the open air 

 are not likely to suffer much from deficient respiration. But 

 persons following sedentary occupations, such as that of the 

 student, not calling for deep breathing (and often the air 

 taken in is of poor quality), need to pay especial attention to 

 the matter. 



The fact has been noted that breathing directly aids the 

 circulation of the blood. This is due to the way air pressure 

 is made to affect the large veins. Breathing also may very 

 considerably aid the flow of lymph. Every deep inspiration 

 brings pressure to bear on the main lymph duct as the dia- 

 phragm descends. Every forced expiration has the same 

 effect. Now, we must keep in mind that the tissues are fed 

 directly by the lymph that surrounds them ; that while the 

 lymph is continually fed by the blood, there is not a great 

 pressure given in this way. The lymph stream is largely de- 

 pendent on the pressure of the surrounding organs. When 

 one takes a good deal of muscular exercise the lymph is re- 

 newed with rapidity enough to supply the tissues with food, 

 and to carry away their wastes. But for those who sit quiet 

 a large share of the day, taking no more exercise than is ne- 

 cessary to take them to and from their places of business, it is 

 well to give this matter especial attention. Deep breathing, 

 regularly practiced several times a day for a few minutes at a 

 time, is very beneficial. 



It is a grateful relief to the whole system to stand, stretch, 

 inhale deeply and slowly several times, and to repeat this 

 every hour or so. Every one engaged in office work or study- 

 ing should form this habit, especially if he does not give an 

 hour daily to exercise in a gymnasium, or otherwise. 



Respiratory Sounds. During respiration sounds are 



