OF THE SKIN IN GENERAL. 211 



sistance or cohesion, which renders it, in the mechanical arts, 

 fit for strong bands. It is submitted in the arts of the tanner, 

 currier, &e. to various processes which prevent its putrefac- 

 tion, and increase its density or flexibility, &c. It contains, 

 naturally, a great quantity of moisture, whose abstraction ren- 

 ders it yellow and elastic. Decoction reduces it into glue or 

 gelatine. Besides its extensibility and retractility, which are 

 very great and which continue after death, it possesses, during 

 life, a very evident tonic power of contraction, although in a 

 much smaller degree than the muscles. It is this contraction 

 which produces what is commonly called goose-flesh. It is 

 its external surface that is the seat of the sense of touch. The 

 dermis 1 is the support of all the rest of the skin; the corpus 

 mucosum is placed on its surface. 



301. The corpus mucosum, of Malpighi,* reticulare cor- 

 pus^ rete glutinosum malpighianum^ is a very thin layer, of 

 a semi-liquid cellular tissue, which clothes the papillary surface 

 of the dermis, separates it from the epidermis, adheres closely 

 to each of them, and is the seat of colouring matter. This part 

 of the skin, indicated by Malpighi, well observed by Meckel 

 and Albinus, acknowledged by most anatomists, at least in the 

 negro, denied, however, by some of them, particularly by Bi- 

 chat, M. Chaussier, Gordon, and M. Rudolphi, can not, it is 

 true, be isolated by dissection, but may be seen in various cir- 

 cumstances. Whenever, either in life or death, the epidermis 

 is separated from the dermis, we can perceive on one or the 

 other, and sometimes on each of these membranes a mucous 

 layer, which covers the papillary eminences, and fills up the 

 spaces between them. This intermediate membrane, is par- 

 ticularly visible in the negro, very visible also in the black 

 spots of the white man, and even very distinct on a piece of 

 white skin, in the collection of Hunter. This layer, extremely 

 thin on the summits of the papillae, and less so in the inter- 

 vals, has the appearance of a net-work, but is not perforated. 



* See Mecke], Rechcrches anatonu'gues sur la nature de Fcpidcrme et du 

 reseau qu'on appclle malphigien, Mem. de Pacad.. roy. des sc. de Berlin, ann. 

 1753. Albinus, Acadcm. annot. lib. i. cap. i. v. 



