The elements of the science of nutrition / by Graham Lusk.

  • Graham Lusk
Date:
1917
Catalogue details

Licence: In copyright

Credit: The elements of the science of nutrition / by Graham Lusk. Source: Wellcome Collection.

    164/850 (page 164)
    However, Zuntz while living on the summit of Monte RosR found that sunlight did not reduce metabolism (p. 585). Hasselbalch1 found that if the naked body of a man was strongly exposed to ultra-violet rays the rate of respiration was diminished while the depth was increased. The skin was red with dilated capillaries and the blood-pressure fell. Lindhard, in 1910, showed there is a yearly periodicity of the respiratory rate in the Arctic region, it being less in the spring and summer than in the winter. The enormous variations in the chemical intensity of the sun’s rays in the Arctic region are undoubtedly the cause of this manifestation. Even in Copenhagen the same phenomenon has been observed by Hasselbalch and Lindhard.2 The volume of respiration increases 26 per cent, in the summer. The intensity of the metabolic processes is not affected. This accords with the fact that there is no change in metabolism through an alteration of the respiratory rhythm induced by cutting the pulmonary branches of the vagus.3 It is reported4 that a considerable reduction in the urinary nitro- gen, creatinin and sulphur excretion occurs in dogs maintained with a constant protein diet when these are irradiated by artificial sunlight from a mercury vapor lamp. Durig and Zuntz5 find that the climate of the seashore does not influence the basal metabolism, nor does travel to the semi-tropical Canary Islands6 nor the condition of sea-sickness. COMPARATIVE METABOLISM OF DIFFERENT RACES A number of comparative observations of the basal metabolism have been made upon various races of men, upon natives and emi- grants, on Chinese living in New York, and on Europeans who have migrated to the tropics. An outstanding contribution is that of Takahira7 whose work has already been referred to. The following table presents results of an investigation concerning the basal metabolism of the Japanese: 1 Hasselbalch, K. A.: Skan. Arch. Physiol., 1905, 17, 431. 2 Hasselbach, K. A., and Lindhard, J .-.Ibid., 1911, 25, 361; Lindhard, J.: Ibid., 1912, 26, 221. 3 Rauber, A., and Voit, C.: “Sitzungsber. der baeyerischen Akademie,” 1868. 4Liebesny, P.: Z. physik. u. diat. Therap., 1920, 24, 182. 5 Durig, A., and Zuntz, N.: Biochem. Z., 1912, 39, 422, 435. 6 For an interesting discussion of the effects of tropical light on white men read C. E. Woodruff, “Medical Ethnology,” New York, 1915. 7 Takahira, H., Kitagawa, S., Ishibashi, E., and Kayano, S.: Abstract in English issued by Imperial Government Institute for Nutrition, Tokio, 1924, p. 41.