INFL UENCE OF A CTIVIT Y ON PRO TEID ME TABOLISM. 9 1 5 
difference in the amount of sugar of the blood passing to and from an 
active muscle has been obtained by Chauveau and Kauf maim ; x such 
differences as are found generally fall within the limits of experimental 
error. Chauveau 2 has further endeavoured to show that in dogs 
muscular work is not effected at all at the expense either of the 
proteids of the body or of the food : but, as I. Munk has pointed 
out, the results obtained cannot be accepted as conclusive. 3 That 
glycogen disappears both from the liver and from the muscles of 
dogs, and from the " surviving " excised muscles of the frog, con- 
comitantly with the production of muscular work, 4 is held to be an 
argument in favour of this work being done at the expense of this 
carbohydrate. Under certain circumstances, however, the glycogen of 
the muscles may be caused to entirely disappear, although they are still 
capable of performing a large amount of work, which must, under 
these circumstances, be otherwise derived, however probable it may 
be that under normal circumstances the oxidation of dextrose or 
glycogen plays an important part in its production. 
In support of the view that muscular energy may be largely derived 
from the oxidation of carbohydrate materials, it has been observed by 
Tiegel, 5 that the Japanese rickshaw runners consume rice in large 
quantities, and at frequent intervals, during their periods of work, 
whereas on off-days they live mainly on a iiesh diet. 6 
Pfliiger 7 kept a dog of 30 kilos, weight in equilibrium upon perfectly lean 
meat, containing a very large preponderance of proteids over non-proteids. 
When caused to pass from a condition of rest to hard work, it lost flesh if kept 
on the same diet, until it assumed a lower position of X-equilibrium, hut main- 
tained or even added to its weight if the amount of flesh was increased 500 
grms. per diem ; about 50 per cent, of the potential energy of the additional 
proteid appearing as work. If now, whilst in N-equilibrium on lean flesh, fat 
and carbohydrate were added to the diet, these were not utilised for the pro- 
duction of energy, but were stored as fat ; hence, Pfliiger argues, the living 
tissue prefers to use the proteid, and only takes non-proteid if insufficient proteid 
is offered to it. It should, however, be pointed out that Pfiuger's dog was, 
with its purely proteid diet, in a condition of extreme emaciation, 8 and the cir- 
1 Compt. rend. Acad. d. se., Paris, 1887, tome civ. pp. 1126, 1352, and 1409. Similar 
results (disappearance of sugar from blood passing through active muscles) have been 
obtained by Morat and Dufourt (Arch, dephysiol. norm, et path., Paris, 1892, p. 327), who 
also found a certain disappearance after the work, which they suppose due to glycogen stored. 
- With Contejean, Compt. rend. Acad. d. sc, Paris, tome exxii. pp. 429, 504. 
3 Verhandl. d. physiol. Gesellsch. zu Berlin, 8 Mai, in Arch. f. Physiol., Leipzig, 1896. 
4 O. Nasse, Arch./, d. ges. Physiol., Bonn, 1869, Bd. ii. S. 97 ; also Weiss, Sitzungsb. d. k. 
Akad. d. TVissensch., Wien, 1876, Bd. lxiv. S. 288; Marcuse, Arch. f. d. ges. Physiol., 
Bonn, 1886, Bd. xxxix. S. 425; Manche, Ztschr. /. Biol, Munehen, 1889, S. Bd. xxv. 
164 ; and ibid., 1877, Bd. xiv. S. 473. 
5 Ibid., 1883, Bd. xxxi. S. 607. 
6 U. Mosso and Paoletti (Atti d. Accad. d. Lincei, Roma, 1893) and V. Harley 
(Proc. Roy. Soc. London, 1893, p. 480, and Journ. Physiol., Cambridge and London, 1894, 
vol. xv. p. 97) using the ergograph of A. Mosso, found that they could perform a greater 
amount of voluntary muscular work when a large amount of cane-sugar was added to the 
diet. Experiments of this nature are, however, liable to a psychical error, and, as a 
matter of fact, experiments by Langemeyer (with Stokvis) made upon different persons 
failed to give similar results (see discussion in Brit. Med. Journ., London, 1895, vol. ii. 
pp. 1280-1285). 
7 Arch./, d. ges. Physiol., Bonn, 1891, Bd. 1. S. 98, and Bd. Ii. S. 317. 
8 It may be, noted in this connection that the " Banting cure" for obesity depends upon 
the principle of selecting a diet not necessarily insufficient, but consisting mainly of lean 
meat. As in the case of Pfliiger 's dog, the tissues under these conditions use up the body- 
fat, which thus becomes gradually reduced in amount. 
