MOVEMENT 



41 



their extremities. It is in this way that the arterial 

 pulse, as it alternately raises and lowers the lever, 

 demonstrates in different patients the condition of the 

 circulation.* "When a movement is on too large a 

 scale to be recorded in its actual size, it must be 



v-JVvJV 



VlWiW/ 



^rvKNK 







Fig. 28. — Enlarged tracings of the pulse in different diseases. 



reduced before transmission to the recording needle. 

 There are several ways of doing this, the following are 

 the most usual methods. The movement can be 

 reduced by allowing it to act on the longer arm of a 

 lever, while the writing needle is placed on the shorter. 



* See Tlie Circulation. Paris, G. Masscm, 1881. 



