PULSE. 



191 



thing in the morning and the last at night, 

 founded on from two to ten observations at 

 each period, in healthy young persons of both 

 sexes, were obtained, with what result will be 

 seen in the following tables. 



STATE OF THE PULSE, MORNING AND EVENING, 

 IN MALES. 



STATE OF THE PULSE, MORNIXG AND EVENING, 

 IN FEMALES. 



The facts contained in these tables and in 

 the previous table, together with the two series 

 of experiments performed by Nick, may be 

 taken to establish the general law first set 

 forth by Dr. Knox, that the pulse is less fre- 

 quent in the evening than in the morning; 

 but it is obviously subject to numerous ex- 

 ceptions. 



This law derives some confirmation from 

 the fact that the only series of experiments 

 on females which the writer has met with 

 (those of Friedrich Hohl on pregnant women f) 

 yield averages in conformity with it ; for on 

 comparing the mean of 25 observations made 



* American Journal of Medical Sciences, vol. v. 

 p. 341. 



f Die Geburtshttlfliche Exploration, bey Anton 

 Friedrich Hohl. 



on the pulses of pregnant women in the morn- 

 ing with a mean of the same number made on 

 the same women in the evening, the pulse in 

 the morning was 83*28, and in the evenin" 

 80-88, being a difference of 2'40. The same 

 author also states that the pulse of the new- 

 born infant, and of the foetus in utero are more 

 frequent in the morning than in the even- 

 ing.* The interval between the morning and 

 evening is filled up by pulses of very variable 

 frequency, where the experiments are not 

 made with due precaution ; but where, as in 

 the second series of experiments by Nick, 

 and in those of Knox, and of the present 

 writer, the body remains in the same posture, 

 in a state of rest, and unexcited by stimu- 

 lating food, the fall in the frequency of the 

 pulse is for the most part progressive, and free 

 from those accelerations at noon and in the 

 evening of which Double and Cullen have 

 made mention. 



The diminished frequency of the pulse to- 

 wards the afterpart of the day seems to de- 

 pend altogether on the exhaustion of the 

 strength, and is a less degree of that marked 

 diminution of frequency which often accom- 

 panies a convalescence from severe disease. 

 That it is not dependent merely on the ab- 

 sence of exertion ; in other words, that it is 

 not the effect of continued rest, is proved by 

 the facts now to be mentioned. 



It has been experimentally proved, both by 

 Dr. Knox and by the writer of this article, 

 that the pulse is not only less frequent in 

 the evening than in the morning, but that it 

 is also less excitable. So marked is the dif- 

 ference in this respect, that in some experi- 

 ments recorded in the Guy's Hospital Re- 

 portsf, the very same food, which in the 

 morning increased the frequency of the pulse 

 from five to twelve beats, and kept it raised 

 above its natural number from one to two 

 hours, produced no effect whatever in the 

 evening. This fact is in strict keeping with the 

 well known effect of spirituous liquors 'in the 

 early part of the day, as compared with their 

 action on the system in the evening. 



The pulse in males appears to follow the 

 same rule in disease as in health. The rule is 

 inverted in females ; but in both sexes the 

 exceptions are very numerous. J 



Rest. From what has already been stated 

 it will be inferred that the absence of exertion 

 has the effect of diminishing the frequency of 

 the pulse. 



Sleep. The pulse falls during sleep, slightly 

 in adults, but considerably in young children. 

 In six observations made by Nick on as many 

 young adults, the mean decrease was some- 

 what more than three beats. Quetelet, in a 

 girl from three to four years of age, found a 



* An average of twenty-five observations on the 

 morning pulse of the foetus in utero gave 138-08 

 beats, and on the evening pulse 135-76, a difference 

 of 2-32 beats. Hohl himself recognizes this fact, 

 and distinctly states that the pulse of the foetus is 

 more frequent in the morning than in the evening:. 



t No. viii. 



J Ed. 'Med. and Surg. Journal, No. 146. 



