269 



CHAP. XVI. 



PERSPIRATION. 



THE skin is not only the organ of touch, but also, like the lungs, 

 an organ of inhalation and excretion. 



It " consists of three membranes: The corium, internal; the 

 cuticle, external ; and the reiiculwn, intermediate. 



" The article, or epidermis a , forms the external covering of the 

 body, is separable into several lamellae b ," though it does not con- 

 sist of imbricated scales , " and is exposed to the atmosphere, the 

 contact of which can be borne by " no " other part, if you except" 

 the hairs and nails, and the feathers, wool, horny hoofs, and 

 claws of brutes, which are really of the same nature with it, and 

 " the enamel of the teeth. For this reason, the internal cavities, 

 and the canals which communicate with the surface for the pur- 

 pose of admitting air, especially the respiratory passages and the 

 alimentary canal," at least as far as the end of the oesophagus, 

 " the tongue, the inside of the cheeks, the fauces, and the organ of 

 smell, are covered by a fine epithelium, originating from the epi- 

 dermis. d 



" The texture of the epidermis is extremely simple, destitute 

 of vessels, nerves, and true cellular membrane, and consequently" 

 not organised ; " very peculiar, however e ; remarkably strong, 



a " Al. Monro ( PRIMUS), ORATIO de Cuticula Humana. Opera. English 

 edition. Edin. 1781. 4to. p. 54. sq." 



b " Among others, consult J. Mitchell, Philos. Trans,, vol. xliii. p. 111." 



c Cloquet, Manuel d'Anatomie descriptive, p. 260. 



d " Abr. Kaau, Perspiralio dicta Hippocrati, p. 7. 



Lieberkiihn, Defabrica Villor. Intestin. Tenuium, p. 16. 



Cruikshank, Expts. on the Insensible Perspiration, p. 5. 



Rudolphi, Reisebemerkungen, t. i. pp. 29. 140. 



Jens. W. Neergaard, Vergleichende Anat. der Verdauungswerkzeuge, p. 21. et 

 alibi. 



J. B. Wilbrand, Hautsystem in alien seinen Verzweigungen, Giessen. 1813. 8vo." 



e " The very dense epidermis of some immense animals consists of vertical fibres, 

 which, in arrangement, somewhat resemble the structure of the Boletus igniarius. 

 Its internal surface is porous, and penetrated by the silky filaments of the sub- 

 jacent corium. This is remarkably exemplified in a preparation now before me, 

 taken from the skin of the balaena mysticete. 



T 



