PULSE. 



193 



it is most probable that it was the recumbent 

 posture; for it is in that posture that the 

 breathing is most easily counted ; and as it is 

 possible, when the subject of the observation 

 is lying down, to place the hand on the abdo- 

 men, still retaining the hold upon the wrist, 

 and to count the breathing while he remains 

 unconscious of the object of the observer, the 

 true number of the respirations, as compared 

 with that of the pulse, may be ascertained 

 with tolerable accuracy. Eighteen such ob- 

 servations, made by the writer on as many 

 healthy young men, gave as the average pro- 

 portion 3'72 to 1, and thirteen observations 

 on as many more healthy and adult females, 

 the proportion of 3'61 to 1. The extremes, 

 in the observations on males, were 2'54 to 1, 

 and 5'33 to 1 ; and in females, 3' 10 to 1, 

 and 4 - 33 to 1. In these observations the re- 

 spiration was counted, immediately after the 

 pulse, for two consecutive minutes. Bryan 

 Robinson, as the result of three observations 

 on the same number of healthy males in the 

 sitting posture, obtained numbers of the 

 pulse and respiration, from which the calcu- 

 lated proportions are 3'82 to 1, 3' 79 to 1, and 

 3-86 to 1. Quetelet*, from a series of 300 

 experiments on males of different ages, ob- 

 tained the following proportions : 



At birth, 3'09 to 1. 



5 years of age, 3'38 to 1. 



15 to 20 - ^ - 3-72 to 1. 



25 to 30 - - 4-43 to 1. 



30 to 50 - - 3-88 to I. 



In his own case, the average proportion 

 was 4'19 to 1. From a smaller number of 

 observations on females, the following pro- 

 portions were obtained : 



At birth, 3'09 to 1. 



15 to 20 years of age, 4' 10 to 1. 



20 to 25 - 4-52 to 1. 



30 to 50 - 3-92 to 1. 



From other observations by the same author, 

 it would appear that the proportion of the pulse 

 to the respiration during sleep is lower than in 

 the same persons awake, in consequence of the 

 respiration being more affected during sleep 

 than the pulse. Thus, in a girl from 3 to 4 

 years of age, the mean proportion of the pulse 

 to the respiration was 3'40 to 1 awake, and 

 3'68 to 1 asleep ; in a boy from 4 to 5 years 

 old, 3'21 to 1 awake, and 3'50 to 1 asleep ; 

 and in a female in her 27th year, 2'85 to 1 

 awake, and 3' 19 to 1 asleep. The averages 

 are deduced from " un asscz grand nombre 

 d' observations" and were probably made in the 

 recumbent posture. 



Drs. Hourmann and Deschambre obtained, 

 as the result of 255 observations on aged 

 females, 3'4 1 to 1, or, excluding extreme fre- 

 quencies both in excess and defect, 3'65 to 1. 

 Dr. Pennock, from 146 observations on aged 

 males, obtained a mean of 3'51 to 1, and 

 from 143 observations on aged females, 3'53 

 to 1. 



As the respiration is greatly under the 

 control of the will, to obtain the requisite ac- 

 curacy in observations of this nature it would 

 be necessary to adopt some measures by 

 which it might be counted for several minutes 

 at least in succession, the subject of the ob- 

 servation being either unconscious of what is 

 going on, or having his attention diverted 

 from it. This object the writer has accom- 

 plished by converting the common pocket 

 pedometer into an instrument for registering 

 the respirations ; and by means of it, has made 

 several hundreds of observations during pe- 

 riods of half an hour each, the pulse being 

 counted for one or two minutes before and 

 after each registration of the respirations, and 

 the average of the two or four minutes being 

 taken to represent the frequency of the pulse 

 during the whole period of the experiment. 

 The greater number of the experiments were 

 made in the sitting posture, with the back 

 supported, the attention being diverted from 

 the breathing by engaging in study.* The, 

 following are the principal results obtained in 

 this manner: the average proportion from 

 238 experiments performed in the manner 

 just described, the pulse varying from 44 to 

 85 beats, and the respiration from 15^ to 20, 

 was 3'47 to 1. The extreme proportions 

 were 2'61 to 1, and 5 to 1. 



The average proportions varied with the 

 number of the pulse, as shown in the following 

 table : 



* Vol. ii. p. 86. 



From the results of these experiments, 

 then, it would appear that the proportion 

 which the pulse bears to the respiration, in 

 the same posture of the body, diminishes as 

 the frequency of the pulse increases. 



Another fact established by these experi- 

 ments is the different frequency of the respira- 

 tion morning and evening for the same fre- 

 quency of pulse. Thus, for a pulse of 63, 

 being an average of 50 experiments in the 

 morning and 50 in the evening, the number 

 of respirations in the morning was 17'60, and 

 in the evening V6'58, being as nearly as pos- 

 sible as the numbers 17 and 18. 



The effect of posture on the respiration, 

 and the proportion which it bears to the 

 pulse, is, however, still more remarkable than 

 that of the time of the day. Thus, to take 

 the only instance in which it was possible to 

 compare the proportion of the pulse to the 



* An abstract of the results of these experiments 

 was first published in the first part of Hooper's Phy- 

 sician's Vade Mecuni, edited by the writer early in 

 the year 1842. 



VOL. IV. 



