INFLUENCE OF FOOD. 
717 
equally under ordinary conditions, so that the respiratory quotient 
remains practically unaltered. It is only immediately after work that 
the respiratory qu< >tient increases, and becomes sometimes greater than 
unity. The absorption of oxygen needed for the work of walking on 
level ground is, per kilo, body weight and minute, 0-1682 c.c. 
maximum, and 0-0858 c.c. minimum; for each kilogrammetre of work 
performed in climbing, T5036 c.c. maximum, and ri871 minimum; and 
similarly, for turning the wheel, T957 c.c. 
Lowy 1 shows that there is no definite value which can be assigned to 
the increase of the respiratory exchange for the performance of a given 
quantity of work under all circumstances, for the metabolism depends 
upon the activity of the muscle, which varies under different conditions. 
Active muscle working under favourable conditions performs its work 
economically; fatigued muscle working under unfavourable conditions 
is the seat of an extravagant metabolism. 2 
The decrease observed in the respiratory exchange of animals under 
the influence of chloroform, ether, chloral, and curari, is to be attributed 
chiefly to the great decrease in the activity of the muscles. 3 
The influence of food upon the respiratory exchange. — The effect 
of a meal upon the respiratory exchange is to cause a marked increase 
in the intake of oxygen and the output of carbon dioxide ; this is due 
Number of 
Experiments. 
Mean Output of Carbon Dioxide 
per Kilo, and Hour. 
Condition of Animal. 
7 
52 
4 
4 
Grms. 
1-423 
0-902 
0-998 
0-732 
C.c. 
723 
458 
507 
372 
Pregnant ; very liberal diet of meat. 
The same animal ; hunger for 18 dys. 
15 „ 
18 „ 
shortly before death. 
6 
2 
23 
12 
0-847 
1-364 
0-888 
0*679 
430 
693 
451 
345 
Male, kept at constant weight with 
diet of meat. 
Male, maximal diet of meat. 
Male, normal diet of meat, but 
without water. 
Male, inanition, but with water 
supplied. 
7 
6 
1-702 
1-500 
865 
763 
Female, not full grown ; diet of 
meat. 
Female, diet of fat. 
1 Arch. f. d. ges. Physiol., Bonn, 1891, Bd. xlix. S. 405. See also, Gruber, Ztschr.f. 
Biol., Miinchen, 1891, Bd. xxviii. S. 466. 
2 For further experiments upon the influence of work upon the respiratory exchange of 
(a) man, see Hanriot and Richet, Ann. d. chirn. et phys., Paris, 1891, Ser. 6, tome 
xxii. p. 495 ; and Trav, du lab. de Ch. Packet, 1894, tome 1 ; (b) animals, Grandis, Arch, 
ital. de bid., Turin, 1889, tome xii. p. 237 ; Smith, Joum. Physiol., Cambridge and 
London, 1890, vol. xi. p. 65. Criticism of the same byZuntz and Lehmann, ibid., p. 396 ; 
Greliant, Compt. rend. Soc. de biol., Paris, 1891, p. 14. 
3 Zuntz, Arch. f. d. ges. Physiol., Bonn, 1876, Bd. xii. S. 522 ; Pfliiger, ibid., 1878, 
Bd. xviii. S. 247; Rurnpf, ibid., 1884, Bd. xxxiii. S. 538 ; Saint Martin, Compt. rend. 
Acad. d. sc, Paris, 1887, tome cv. p. 1126 ; Richet, ibid., 1889, tome cix. p. 190 ; Arch, 
dc 2>hysiol. norm, ctpath., Paris, 1890, tome ii. p. 221 ; Pembrey, " Proc. Physiol. Soc," 
Joura. Physiol., Cambridge and London, 1894-95, vol. xvii. 
