RESPIRATION. 



die finder of the right hand as a hammer, percuss the entire chest 

 wall. Explain the variations in the percussion note over various 

 regions. Map out the heart and the liver. 



6. Chest Measurements. (a) Let a student strip to the 

 waist. Measure the chest circumference at the axillae at the end 

 of quiet inspiration and at the end of quiet expiration. Repeat 

 this measurement at the level of the end of the sternum. Re- 

 peat both measurements, in forced inspiration and expiration. 

 Record results. 



(b) In the same individual measure the antero-posterior tho- 

 racic diameters at the junction of the first and second pieces of the 

 sternum and at the end of the sternum, during inspiration and ex- 

 piration, both quiet and forced. Measure the changes in the lat- 

 eral diameters in the same way. A pair of long, graduated calipers 

 serves for the purpose of making the measurements. Record results. 



For purposes of comparison, measure the length of the trunk 

 from the "vertebra prominens" to the level of the chair upon 

 which the subject is sitting. Repeat these measurements on other 

 students and keep a record for each individual. 



6. Respiratory Capacity. This is usually determined by 

 some form of water spirometer. A long, narrow cylinder, gradu- 

 ated in cubic centimetres, is filled with water and inverted over 

 water in another cylinder. An air tube passes through the second 

 cylinder to the top of the first. The first cylinder is counterpoised 

 by weights and pulleys, so that when air is forced into it the water 

 is displaced, the cylinder rises, and the amount of water displaced 

 by air can be read off on the attached scale. 



(a) Calibration of Spirometer. The air cylinder of the spirom- 

 eter should be calibrated before using. This may conveniently 

 be done in the following way: Fill the cylinder with air; note the 

 position of the pointer on the scale; place the outlet air tube under 

 a graduated 1000 c.c. cylinder, filled with water and inverted over 

 water, in a large pan or tub ; slowly depress the spirometer cylin- 

 der until the pointer has passed five or ten spaces of the scale, and 

 read off the amount of water displaced from the graduated cylin- 



