FREQUENCY OF THE HEAET's ACTION. 



213 



ence in the rapidity of the pulse in the sexes ; but towards 

 the age of puberty, the development of the sexual peculiarities 

 is accompanied with an acceleration of the heart's action in 

 the female, which continues even into old age. The differ- 

 ence at different ages is shown in the following table, com- 

 piled by Milne-Edwards from the observations of Dr. Guy : J 



Influence of Digestion. The condition of the digestive 

 system has a marked influence on the rapidity of the pulse. 

 According to observations cited by Milne-Edwards, 2 there is 

 an increase in the pulse of from five to ten beats per minute 

 after each meal. Prolonged fasting diminishes its frequency 

 from twelve tor fourteen beats. Alcohol first diminishes, and 

 afterwards accelerates, the pulse. Coffee is said by the same 

 author to accelerate the pulse in a marked degree. It has 

 been ascertained that the pulse is accelerated to a greater 

 degree by animal than by vegetable food. These variations 

 have long been recognized by physiologists. 



Influence of Posture and Muscular Exertion. It has 

 been observed that attitude has a very marked influence upon 

 the rapidity of the action of the heart. Experiments of a 



1 Lemons sur la Physiologic, tome iv., p. 62. 



2 Loc. cit. 



