564 



The determination of percentage quantities is worthless for this 

 purpose, unless the total quantities of air or urinary water he also 

 ascertained and employed in the calculation. As the per-centage 

 quantities vary greatly, it is necessary that the daily quantities be de- 

 termined to a uniform hour ; and the best period is that which imme- 

 diately precedes breakfast. 



2. General considerations affecting each subject of inquiry. 

 PULSATION AND RESPIRATION*. 



In instituting any inquiries into the rate of pulsation and respira- 

 tion, the following conditions are required : 



The posture of the body must be uniform ; and as the sitting pos- 

 ture has a rate nearly intermediate between that of lying and 

 standing, it should be universally preferred, except in inquiries into 

 the influence of sleep, or on the sick often confined to the couch, when 

 inquiries in the lying posture are alone practicable. The posture 

 should remain quite unchanged during the whole time of the inquiry, 

 also for at least five minutes before its commencement, if the person 

 has been previously at rest, and fifteen minutes in the case of previous 

 exertion. The attention must be withdrawn. Care should be given 

 to ascertain if the rate is influenced by a feeling of nervousness, or by 

 any other disturbing cause ; and if so, the inquiry must be deferred 

 until the rate has become uniform. There are also conditions, how- 

 ever absurd it may appear, when the observer is liable to mistake the 

 pulsation in his thumb or finger for that of the person under inquiry. 

 The rate should be counted during two minutes if practicable, and in 

 no instance less than one minute. Half a respiration should be re- 

 corded ; and the counting should be commenced only from a long line 

 on the watch dial. It is often very difficult to count the respirations 

 during quiet sleep in the night, and even during wakefulness, in many 

 women, notwithstanding close observation of the movements of the 

 alse of the nose and of the upper part of the chest ; and in such cases 

 the hand must be slightly applied to the chest. Coughing, yawning, 

 and dreaming temporarily accelerate the pulse. It occasionally occurs 

 that the rate of respiration or pulsation becomes doubled or halved ; 

 and intermitting pulsation often occurs in children and feeble persons 

 during sleep, whether by night or day. In comparing the rates upon 



* See Medico-Chirurgical Transactions, vol. xxxix. 1856. 



