THE CIRCULATION OF THE BLOOD 89 



To Adjust the Sphygmograph. (1) Let the observer stand with 

 his right foot on a chair. This brings his thigh into a horizontal 

 position. 



(2) Let the subject stand at the right of the observer, resting 

 the dorsal surface of the left forearm upon the observer's knee. 



(3) Let the observer with pencil or pen mark the location of 

 the radial artery. 



(4) Let the observer wind the clockwork which drives the tracing 

 paper; adjust the latter in readiness for tracing; rest the instru- 

 ment upon the subject's arm with its foot on the radial artery and 

 adjust the position, tension, and pressure in such a manner as to 

 obtain the maximum amplitude of swing of the tracing needle. 

 Take the tracing. Fix in damar-benzole solution. 



3. Observations, a. The Location, etc., of the Radial Artery. (1) 

 What are the relations of the radial artery at the distal end of the 

 radius ? 



(2) How may the relations vary? 



(3) Is there any variation, among the members of the division, 

 in the location of the radial artery? 



(4) May excessive muscular development affect the ease with 

 which the artery may be located and its pulsations studied? 



(5) May excessive deposit of adipose tissue hinder the observations 

 of the pulse? 



(6) May faulty position of subject or of his clothing affect the 

 pulse? 



b. The Digital Observation of the Radial Pulse. (7) Feel the 

 pulse with the side or back of the finger, then with volar surface and 

 tip of each finger of each hand, and note the finger or fingers with 

 which the feeling is most acute. It will be wise to always use these 

 fingers in all tactile examinations. Their acuteness of feeling will 

 increase with practice. One may thus acquire the educated touch 

 tactus eruditus. 



(8) How much may be learned of the pulse by means of the touch 

 alone? Observe and note: (a) rate; (b) rhythm; (c) volume; (d) 

 strength; (e) compressibility; (/) may anything else be determined 

 by this method? 



c. The Sphygmogram. (9) Take at least three pulse tracings of 

 each individual in the division, (a) Compare the tracings taken 

 from one individual; if they differ, determine the cause of the differ- 

 ence, (b) Compare the tracings of different members of the division. 

 Determine, if possible, the cause of the differences. 



(10) Do variations of the relations of the artery affect the sphygmo- 

 gram? Does the adjustment affect the sphygmogram? Does the 

 elasticity of the artery affect the tracing? How does strength or 

 rate of heart beat affect it? 



Make a list of the facts regarding the condition of the circulatory 



