On the functions of the colouring matter of the skin in the dark races of mankind / by Robert Mortimer Glover.

  • Glover, Robert Mortimer, 1816-1859.
Date:
[1840?]
Catalogue details

Licence: Public Domain Mark

Credit: On the functions of the colouring matter of the skin in the dark races of mankind / by Robert Mortimer Glover. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    The notions entertained at present by physiologists, with regard to the operation of this pigment, are implicitly those of Sir Everard. And what they are, will appear from the fol- lowing brief quotation from an elementary work :— The se- cretion on the cutis vera, which gives the black colour to the skin, appears to assist in fitting men for residence in hot cli- mates, because although such skin, by absorbing more caloric, rises to a higher temperature under the sun's rays than white skin does, yet it does not inflame so readily from a rise of tem- perature. Dr Alison's meaning is, that although the skin of a negro may rise to a higher temperature under the sun's rays than a white skin in the same circumstances, yet the dark skin is less likely to inflame at that higher temperature than the white skin at that lower one. This, then, is the conclusion of Sir Everard Home, whose paper I now proceed to examine. The paper of Sir Everard Home contains alleged facts and experiments, tending to prove the Negro more capable of with- standing excessive heat of the sun's rays than the white man, and attributing this to a supposed property in dark surfaces of destroying the scorching and blistering effect of the sun's rays. The former conclusion has already been admitted. The facts by which Sir Everard supports his second position are to be considered. Sir Everard having fallen asleep on the deck of a vessel ex- posed to a tropical sun, found, on awaking, his thigh scorched through a pair of thin white linen trousers. From this simple observation, the extravagant conclusion is drawn of black be- ing a better protection against the sun's rays than white. An experiment is next related, in which Sir Everard found, on exposing his hand to the sun's rays for 45 minutes, while a thermometer attached to it stood at 90°, that blisters rose and coagulated lymph was exuded. I have attempted to produce the same effect by the concentrated rays of the sun at the same temperature indicated in a similar way, and kept up to within one or two minutus of the time, when my patience was ex- hausted, without any result except slight reddening. Six years ago, while off the coast of Algiers, I sat for half an hour im- moveable in the sun, having the greater part of my face ex- posed, the thermometer in the sun's rays being considerably