Licence: In copyright
Credit: On means for the prolongation of life. Source: Wellcome Collection.
Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.
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![skin and hair we may refer to Sir Malcolm Morris in the Book of Health [80]. In connection with the skin we must say a few words about the hair, which is not a mere appendix or ornament, but also an organ of protection. The hair undergoes, with the advance of age, considerable changes, which are especially noticeable in the hair of the head, including the beard, and which MetchnikofF ascribes to the action of the makrophages. There is a wide difference in different persons with regard to the quantity and nature of the hair and the changes occurring in it during life. There are whole families in the members of which the hair begins to turn grey already at 20 or soon after, while in other families the hair retains its original colour up to 60 or 70 or even 80 or the end of life. Similar is the difference with regard to the loss of hair which commences in some families before 25, while members of other families retain their hair up to the most advanced age. The mere change of colour in itself exercises, especially when it is due to a family peculiarity, no influence on health, but it is sometimes connected with per- manent or transitory changes in more vital parts of the body ; the rapid change from the natural](https://iiif.wellcomecollection.org/image/b2398465x_0191.jp2/full/800%2C/0/default.jpg)
