ON THE MOTION OF THE BLOOD. 69 



infant, in which, while placidly sleeping, it is about 

 140 in a minute. 



Towards the end of the first year, about 124 



second . . . 110 



third and fourth 96 



When the first teeth begin to drop out . 86 



At puberty 80 



At manhood 75 



About sixty 60 



In those more advanced, I have scarcely twice found 

 it alike. 



116. The pulse is, ceteris paribus, more frequent 

 in women than men, and in short than tall persons. 

 A more constant fact, however, is its greater slowness 

 in cold climates.* Its greater frequency after meals 

 and coition, during continued watchfulness, exercise, 

 or mental excitement, is universally known. (B) 



117. The heart rather than the arteries is to be re- 

 garded as the source of these varieties. 



Its action continues in this manner till death, and 

 then all its parts do not, at once, cease to act ; but the 

 right portion, for a short period, survives the left, f 



For since the collapsed state of the lungs impedes 

 the course of the blood from the right side, and the 

 veins must be turgid with the blood just driven into 



* J. H. Schonheyder, De Resolution* et Impotentia motus Muscularis. 

 Hafn. 1768. p. 15. With which work compare the observations of F. Gabr. 

 Sulzer, Naturgesch. des Hamsters, p. 169. 



f Stenonis, Act. Haffniens. T. ii. p. 142. 



Sometimes, though rarely, it happens that the right portion of the heart, 

 oppressed with too much blood, becomes, contrary to what usually takes place, 

 paralysed before the left. This I have more than once observed on opening 

 living mammalia, particularly rabbits. 



