RETE MUCOSUM. 333 



branes, as it is elsewhere ; though taking all things into consi- 

 deration, it is probable that it exists also at these several places* 

 but much finer. It is so extremely thin, and of such a soft muci- 

 laginous consistence, that it is difficult to separate it as a distinct 

 lamina, either by maceration or by any other means ; for it most 

 commonly peels off by adhering to the cuticle, after the man- 

 ner of a pigment. It, however, by good management, may be 

 fairly raised as a membrane, and separated for a certain dis- 

 tance from the other two coats of the skin. 



Fine as this membrane is, it would seem, from the observations 

 of Mr. Cruikshank* upon a negro dead from small-pox, and upon 

 an injection executed in London, by the late Dr. Baynham, of 

 Virginia,! and from more recent experiments in Paris, by M. 

 Gaultier,J that it consists in several layers. 1. Upon the in- 

 equalities or papilla? of the cutis vera, there is a layer called, by 

 M. Gaultier, bloody pimples, (Bourgeons Sanguins,) but which, 

 in the opinion of some other anatomists, are only the papillae 

 themselves of the cutis vera. 2. Then there is a very thin and 

 transparent coat, called, from its colour, Tunica Albida Pro- 

 funda: it is especially visible in the negro; under the coloured 

 horns and scales of animals, and beneath the nails of white per- 

 sons. 3. Over this layer is spread another, (the Gemmula,) 

 which contains the colouring matter of the several complexions 

 of the human family, and consists in a multitude of dark brown 

 points in the negro ; it is visible also in those forms of disease 

 called ephelides (freckles,) by the French, where the skin be- 

 comes spotted; it is not so distinct in the healthy state of the 

 white individual. 4. The last lamina of rete mucosum, is called, 

 by M. Gaultier, Tunica Albida Superficialis, from its whiteness 

 and superficial situation : in many animals it is very distinct, 

 in the negro somewhat so, but in the white it is not to be seen 

 except under the nails, about the hair, and under accidental 

 horny excrescences. 



These observations of M. Gaultier have been verified by M. 

 Dutrochet, in experiments upon the texture of the skin of ver- 



* Expts. on Perspiration. London, 1795. 

 t Wistar's Anat. vol. i. p. 394. 



t Recherches sur la peau, Paris, 1809; in Anat. De L'Homme,par J. Cloquet. 

 PI. cxvu. 



Journal de Physique, May, 1819. Journal Complementaire, vol. v. 



