INFL UENCE OF DA Y AND NIGHT. 
Soi 
Morning. 
(7 9 A.M.) 
Noon. 
Evening. 
| Newly born . 
Children 
Adults J *J- en ' • 
( \\ omen . 
Aged .... 
37°-41 
■i7 37 
37°-0 
37°'22 
37°"25 
-7-80 
38 5 -07 
37°-25 
37° "55 
37°-58 
37 c 61 
37 -12 
36 3 -60 
37°-10 
37^31 
, 
$7 
+ i 
r 
^M 
Si : , 
The following curve x (Fig. 79) represents the mean results of records 
of the temperature of the urine taken by Eichet, Gley, and Eondeau ; the 
times of meals were 7 a.m., 11 a.m., and 7 p.m., and no observations were 
made between 9 o'clock in the evening and 7 o'clock in the morning. 
Daily variations in 
temperature, similar to 
those already described, 
have been observed in 
natives of different 
races living in the 
tropics. 2 
As regards the 
causes of the daily 
variation in tempera- 
ture, muscular activity 
and food appear to be 
the most important 
factors. In ordinary 
life man is most active 
and takes food during 
the day, and is least 
active during the night. 
Debczynski 3 found that 
continuous work carried on throughout the night reversed the variation, 
so that the maximal temperature .">7 D- 8 occurred in the morning, and the 
minimal 35 0, 3 in the evening. Night-watching without work had a similar 
but smaller effect, the maximal temperature 37°*7 being in the morning, 
the minimal 37°"5 in the evening. Jaeger 4 has obtained similar results, 
and Krieger 5 states that work during the night and rest during the day 
reverse the daily variation. The influence of inversion of the ordinary 
routine of daily life has been studied by U. Mosso 6 ; a series of observa- 
tions of the rectal temperature was first made during a period when work 
was performed in the daytime and sleep taken at night, and the two chief 
meals were at 11 a.m. and 6 p.m. ; then there followed another period in 
which sleep was taken during the day and work performed at night, and 
1 Richet, Rev. sclent., Paris, 1885, tome ix. p. 430. 
2 Davy, "Researches," London, 1839, vol. i. p. 169 ; Jousset, Arch, de mid. nav., Paris, 
1883, tome xl. p. 124 ; Maurel, Bull. Soc. d'anthrop. de Paris, 1884, tome vii. p. 381. 
3 Jahresb. ii. d. Leistung. . . . d. ges. Med., Berlin, 1875, Bd. i. S. 248. 
4 Jaeger, Deutsches Arch. f. Tclin. Med., Leipzig, 1881, Bd. xxix. S. 533. 
5 Ztschr.f. Biol., Miinchen, 1869, Bd. v. S. 479. 
6 Arch. Ital. de biol., Turin, 1887, tome viii. p. 177. 
VOL. I. — 51 
Fig. 79. 
—Curve of daily variation in the temperature of 
the urine. 
