The hair : its growth, care, diseases, and treatment / by C. Henri Leonard.

  • Leonard, C. Henri (Charles Henri), 1850-1925.
Date:
1880
Catalogue details

Licence: Public Domain Mark

Credit: The hair : its growth, care, diseases, and treatment / by C. Henri Leonard. Source: Wellcome Collection.

    44/328 (page 40)
    that will absorb the exhaled and transpired material from our bodies—for the lungs and skin are the main sewers—just so long will society be imposed upon by this undoing quality of fashionably-dressed heads of hair. This hydroscopic quality has been taken advantage of in the manufacture of certain scientific instruments. Thus, in certain of the so-called aneroid barometers, the working force is but the extension and contraction of hair under the influence of moisture, and the measured amount of this extension or con- traction is read upon the dial plate in the translated terms of either fair or foul weather. In hot, dry climates the hair of a straight-haired European assumes the locks of the ancient Jove. A good instance of this is given by Mr. St. John, in his Travels in the Valley of the Nile. He says: The effect of the climate of Egypt upon the hair is remarkable. Why, our beard, which in Europe [all Europeans have an ovoid hair, and hence it is curlingly inclined from this anatomical peculiarity] was soft and silky and almost straight, began immediately on my arrival in Alexan- dria to curl, grow crisp and strong, and before I reached Es-so\ian resembled horse hair to the touch, and was also disposed in ringlets about the chin. This is, no doubt, to be accounted for by the extreme dryness of the air. * * * On my return to Malta my curls had all disappeared. Mr. St. John accounted for the curly-headed condition of the Negro in this wise: The extreme dryness of the air, which, operating through several thousand years, has in the interior changed the hair of the Negro into a kind of coarse wool. Undoubtedly Mr. St. John is partially right, for it is the tendency of all ovoidal hair to curl, and especially so in a dry climate, or under anti-hydroscopic conditions. As to the hair of the Negro being coarse wool, one of our most competent