The preservation of the hair / by R.W. Leftwich.

  • Leftwich, Ralph Winnington, 1849-1919
Date:
1910
Catalogue details

Licence: In copyright

Credit: The preservation of the hair / by R.W. Leftwich. Source: Wellcome Collection.

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    ; is of great importance, and on tracing it backwards it is found to have originated in what looks like a rounded patch. The patch is seen by a trained eye ; to be a gland, and as the liver manufactures bile, so does this gland manufacture the waxy or greasy substance which in health is nature’s lubricant for the hair, but which in a certain morbid condition 1 (seborrhcea) dries into crusts on the scalp, or powders off from it as dandruff. The grease has some resemblance to tallow, and is hence called by the Latin name of that substance, sebum, or some- times “ sebaceous matter,” and the gland is known as the “ sebaceous gland,” while a follicle unprovided 1 with a hair is termed a “ sebaceous follicle.” I The narrow neck and mouth of the follicle render it liable to be blocked up, especially in cases of seborrhoea. Bacilli are thought by some to be the principal agent in producing this affection; but a mechanical cause would fully account for the loss of hair which is entailed. The sebaceous matter, continually forming, but unable to escape, exercises a backward pressure upon the papilla, and by lessening its supply of blood causes the hair, first to waste, and secondly, to fall out. The general direction of the follicle is oblique—in that of the “ lay ” of the hair; in shock-headed individuals, I presume it is at right angles with the scalp. The