THE MOTION OF THE BLOOD. 177 



It is commonly believed that the pulse [of every person is 

 quicker in the evening than in the morning, and some have sup- 

 posed an increase of quickness also at noon. Upon these suppo- 

 sitions Dr. Cullen builds his explanation of the noon and evening 

 paroxysms of hectic fever u , as others had theirs of the evening ex- 

 acerbations of all fevers v , regarding them as merely aggravations 

 of natural exacerbations. The existence of the noon paroxysms 

 is doubtful, and the evening one cannot be so explained, if Dr.R. 

 Knox is correct w , though he is opposed to Haller, &c. His ob- 

 servations make the pulse to be slower in the evening, and quicker 

 in the morning. 



Dr. Heberden saw a woman fifty years of age, who had always 

 an intermitting pulse, yet an able anatomist could discover nothing 

 unusual after death ; and two persons whose pulse was always 

 irregular in strength and frequency when they were well, and be- 

 came quite regular when they were ill.* 



" The heart rather than the arteries is to be regarded as 

 the source of these varieties, which we have, therefore, detailed 

 here. 



" 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, y 



" For, since the collapsed state of the lungs after the last ex- 

 piration impedes the course of the blood from the right side, 

 and the veins must be turgid with the blood just driven into them 

 from the arteries, it cannot but happen that this blood, driving 

 against the right auricle, must excite it to resistance for some 

 time after the death of the left portion of the heart. 



" This congestion on the right side of the heart, during the 

 agony of death, affords an explanation of the small quantity of 

 blood found in the large branches of the aorta. 



u Practice of Physic. 



v Haller, El. Physiol. t. ii. p. 263. 



w Edinburgh Medical and Surgical Journal. 1815. 



x Transactions of the Cottege of Physicians. London, vol. ii. p. 31. Similar 

 cases are mentioned by Shenkius, De Haen, Monro, Rasori, and Andral. 



y " Stenonis, Act. Hafniens. t. ii. p. 142. 



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

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

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

 living mammalia, particularly rabbits." 



N 3 



