XXIII. The pulse, sphygmographs and sphygmograms. 



1. Appliances. A sphygmograph; tracing slips; a fish-tail 

 gas jet, or kerosene lamp. 



2, Preparation. Smoke about two dozen tracing slips. 



j. Operation. That the sphygmograph is so little used by 

 the general practitioner may be attributed to the fact 

 that hurry of business, or some other cause, has hin- 

 dered him from making himself thoroughly conversant 

 with the adjustment and use of the instrument, with its 

 limitations and with the interpretation of the tracings. 

 To adjust the sphygmograph. 



First. Let the observer stand with his right foot on a 

 chair. This brings his thigh into a horizontal position. 



Second. Let the subject stand at the right of the ob- 

 server, resting the dorsal surface of the left forearm upon 

 the observer's knee. 



Third. Let the observer with pencil or pen mark the 

 location of the radial artery. 



Fourth. Let the observer wind the clockwork which 

 drives the tracing paper; adjust the latter in readiness 

 for tracing; rest the instrument upon the subject's arm 

 with its foot upon the radial artery and adjust the posi- 

 tion, tension and pressure, in such a manner as to obtain 

 the maximum amplitude of swing of the tracing needle. 

 Take the tracing. Fix. 

 ^. 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? 



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