563 



the above-mentioned subjects of inquiry, since it depends more upon 

 the conditions of the preceding day, and upon the variations in the 

 amount of fluid ingesta. It is, however, the least during the night, 

 and then in the morning before breakfast, but it is not stationary at 

 the latter period. It rapidly increases after breakfast for the space 

 of about three hours, and then decreases even more rapidly, and 

 continues low, notwithstanding the early dinner, until the tea hour, 

 after which it again rises, and finally it falls at about 9 or 10 P.M. 

 until the night -rate is attained. 



The rate of production of urinary water follows the order of that 

 of the emission of urea, except that the increase in the afternoon is 

 much less, and there is an approach to uniformity of production 

 after about 3 P.M. 



Hence, with the exception of the excretion of urea after the early 

 dinner and of urinary water in the afternoon, there is a progressive 

 increase followed by a progressive decrease in all the subjects of in- 

 quiry after each meal, and therefore several such alternations occur 

 during each day. There is also a low rate in the night and imme- 

 diately before each meal. 



The only correct method of determining the daily quantities is 

 to collect the whole. This may be effected at rest, or with mixed 

 rest and exertion, in reference to the urea and urinary water. So 

 also in reference to the air inspired and carbonic acid expired, except 

 that as to the latter the degree of exertion must be limited, and at- 

 tention to the daily duties of life nearly intermitted. I do not think 

 that the total number of pulsations and respirations can be recorded 

 except by the process of counting, since the registering instruments 

 are liable to fail, and an error cannot be corrected. The nearest ap- 

 proach to correct results, short of the foregoing, will be made by ob- 

 servations taken at regular and frequent periods during the 24 hours ; 

 but the period of intermission must not exceed one hour, and it need 

 not be more than a quarter of an hour. 



A rough estimate may be obtained by taking the average of the 

 four maxima and four minima of the rate of pulsation and respiration, 

 and the quantity of air and carbonic acid, if the inquiry be limited to 

 the 18 working hours of the day, viz. 6 A.M. to midnight. If the 

 meals be taken at 8J A.M., 1^, 5|, and 83- P.M., the periods of in- 

 quiry will be 8 and 10J A.M., 1, 3|, 5, 7, 8, and 10 P.M. 



