120 



j?RACTtCAt> PHYSIOLOGY 



heart comes in contact with the chest wall in each posture. Apply 

 the button of the cardiograph to the seat of the impulse, and fix it with 

 tapes. One tape is fastened round the chest and one over the right 



Flo. 118. Impulse curve of boy aged 15. Tlie moments when the heart sounds were 

 heard are marked. Time marked in fifths of a second. (L.H.) 



shoulder. Connect the cardiograph by means of a J_ ^ UDe w ^^ a 

 recording tambour, and take records on a moderately fast drum. The 

 J_ tube is used to regulate the pressure in the tambour. A small metal 



Fio. 119. Form of impulse curve changed by altering the position of cardiograph. 

 In 3 the chest wall is sucked in during the systolic output. Time marked in fifths 

 of a second. (L.H.) 



box the size of a penny and open at the bottom does very well, if 

 connected to a tambour and pressed over the region of the apex. To 

 interpret the curve, adjust another receiving tambour to the carotid 

 pulse and arrange the writing styles of the receiving tambours to write 



