136 THE CIRCULATION 



at the Grands Mulets it was 88, at Chamounix 56 ; normally, 

 his pulse is 60. 



In health there is observed a nearly uniform relation 

 between the frequency of the pulse and of the respirations ; 

 the proportion being, on an average, one of the latter to 

 three or four of the former. The same relation is generally 

 maintained in the cases in which the pulse is naturally 

 accelerated, as after food or exercise : but in disease this 

 relation usually ceases to exist. In many affections accom- 

 panied with increased frequency of the pulse, the respira- 

 tion, is, indeed, also accelerated, yet the degree of its 

 acceleration bears no definite proportion to the increased 

 number of the heart's actions : and in many other cases, 

 the pulse becomes more frequent without any accompany- 

 ing increase in the number of respirations ; or, the 

 respiration alone may be accelerated, the number of 

 pulsations remaining stationary, or even falling below 

 the ordinary standard. (On the whole of this subject 

 the article Pulse, by Dr. Guy, in the Cyclopaedia of 

 Anatomy and Physiology, may be advantageously con- 

 sulted). 



The force with which the left ventricle of the heart con- 

 tracts is about double that exerted by the contraction of 

 the right : being equal, (according to Valentin) to about 

 ^th of the weight of the whole body, that of the right 

 being equal only to T ^th of the same. This difference 

 in the amount of force exerted by the contraction of the two 

 ventricles, results from the walls of the left ventricle being 

 about twice as thick as those of the right. And the dif- 

 ference is adapted to the greater degree of resistance 

 which the left ventricle has to overcome, compared with 

 that to be overcome by the right : the former having to 

 propel blood through every part of the body, the latter 

 only through the lungs. 



The force exercised by the auricles in their contraction 

 has not been determined. Neither is it known with what 



