ACCORDING TO BRESCHET AND ROUSSEL DE VAUZEME. 427 



back of the epidermic ridges, formed over the papillary bodies. 

 These are the orifices from which the sweat exudes, and may 

 be readily seen with a single lens of moderate magnifying 

 power, on the palms of the hands, soles of the feet, nose, and 

 other portions of the body. The obliquity of the orifice, gives 

 it a valvular arrangement, like that of the ureters where they 

 enter the bladder. In consequence of this the valve closes the 

 orifice, when the epidermis is raised by cantharides, and the 

 duct is broken off, so that the pores are not generally visible ; 

 this has occasioned some anatomists, of great reputation, (J. 

 F. Meckel, Cruikshank, Blumenbach, etc.)* to deny altogether 

 the porosity of the epidermis, and to believe that the sweat 

 passed by exudation or exosmosis directly through its sub- 

 stance. In carefully elevating the cuticle from the subjacent 

 coats, these ducts are visible as very fine transparent elastic 

 filaments ; the spiral being converted into straight tubes by the 

 traction, and which W. Hunter, Bichat, and Chaussier, accord- 

 ing to these writers, mistook for the exhalent and absorbent 

 vessels.f Others supposed they were filaments of cellular 

 tissue, uniting the epidermis to the subjacent layer.J The 

 sudoriferous organs, which are exceedingly numerous, are 

 probably the only exhaling organs of the skin. 



The Inhaling Apparatus. 



This is properly an appendage of the absorbent system ; and 

 may be seen, according to these anatomists, with a lens of 

 feeble magnifying power, or even with the naked eye, in rais- 

 ing the epidermis with proper precaution. They have not, 

 however, been enabled to make out their anatomy satisfactorily. 



* Beclard was disposed to consider these pores as the orifices of the sebace- 

 ous glands, though he expresses himself doubtingly upon the subject, and says 

 that the rout by which the sweat traverses the epidermis is entirely unknown. p. 



f The existence of exhalent vessels, was a mere presumption of Bichat, and 

 has never been demonstrated. p. 



| Eichhorn has also observed these sudoriferous canals, and his description 

 of them corresponds in' many respects with that of Breschet. (Memoire sur 

 les exhalations que se font pour le peau, et sur la voies par lesquelles elles sont- 

 lieu ; par Henri Eichhorn.) Arch, de Meckel. p. 



