SUGGESTIONS FOR LABORATORY WORK 621 



With the pneumograph in place and the back to the apparatus 

 get a record of normal breathing. 



Note the rate per minute. 



Sip the contents of a glass of water. Observe the effect of swal- 

 lowing on breathing. 



Obtain records of reading aloud, of coughing. Compare these 

 with normal, quiet breathing. 



The Control of Breathing. The students of a pair should act 

 alternately as subject and observer in the following tests. Obtain, 

 by counting the breathing movements, the normal rate per minute. 

 Let the subject run down and up stairs. Determine the rate per 

 minute every three minutes till the normal rate is restored. 



Determine how many seconds the subject can hold his breath. 

 Note the difference according to whether he begins to hold it at 

 the end of inspiration or the end of expiration. 



Let the subject breathe rapidly and deeply for two or three 

 minutes and then hold the breath. 



Note the time of holding it as compared with the former trials. 



Repeat the experiment, this time breathing into and from a 

 paper bag. Compare the time the breath can be held with former 

 trials. 



The automatic stimulus for breathing depends on the amount 

 of carbon dioxide in the blood, and indirectly on the amount in 

 the alveoli of the lungs. The experiments on breath-holding can 

 be explained on this basis. 



Artificial Respiration. The Schafer Method. In this experiment 

 the subject should cease breathing so far as possible. The treat- 

 ment may be considered successful when no active breathing 

 movements are necessary. 



Lay the subject prone, with a thick roll of clothing under the 

 chest and the epigastrium. Take a position over or beside the 

 subject's legs, and facing his head. Place the hands on either 

 side over his lowest ribs. Slowly throw the weight of the body 

 onto the hands, and thus compress the subject's thorax and force 

 air from the lungs. Without removing the hands, release the 

 pressure. The chest by its own elasticity will perform the func- 

 tion of inspiration. Repeat this procedure at the normal rate of 

 respiration until the issue is determined. In case of drowning 

 it may be a half hour before respiration is restored. Schafer'a 



