A treatise on the human hair, and its diseases / by Bela C. Perry.

  • Perry, Bela C.
Date:
1859
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the human hair, and its diseases / by Bela C. Perry. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    nal, like the external, is covered by a similar skin, which from its constantly moistened condition, is de- nominated mucous membrane or lining; and on the surface of the various joints, the external is continu- ous with the internal skin or mucous lining, and in these situations, from their similarity of structure, it is difficult to distinguish between them. This difficulty is increased by the circumstance, that when a portion of skin is made to occupy an in- ternal position, it assumes the humid character of muoous membrane; and when a portion of the latter becomes external, it loses its moisture by evaporation and assumes the ordinary appearance of skin. This reciprocal metamorphosis of the two great in- vesting membranes of the body, is frequently wit- nessed in domestic life, and is, therefore, alluded to in this place. Their existence, obviously, depends on the analogy of structure subsisting between them; hence the im- portance of that medical law which is founded on their continuity and similarity. This law resolves itself into four conditions, namely: that disease which affects a part of a membrane is liable to debilitate the whole ; secondly, any disease of the mucous lining may spread to the skin; thirdly, any disease of the skin may affect the mucous lining; and fourthly, that disease of a part of a mucous membrane may become transmitted to a distant part