J92 On the Sense of Feeling. 



its vital and oeconomical uses. We next proceed to some of the subordinate 

 structures which it contains. 



The upper surface of tiie dermis is studded with conical papillae, ar- 

 ranged in rows. Into these papillae the terminal branches of tiie nerves 

 may be traced, and the filaments are found on entering the base of each to 

 assume somewhat of a pulpy structure, of which in fact the whole papilla 

 is formed. 



These papillae are therefore considered to be the actual organs of tact; 

 they vary in bulk, length, and frequency, in various cases, and tiiey derive 

 from the outer layer of the dermis a regular siieath, and are still further 

 protected from any inconvenient pressure, by the horny substance of the 

 epidermis, into which they pass obliquely, as a sword into its scabbard 



Deeply lodged in the dermis are a series of small glandular bodies, sup- 

 plied with blood from the neighbouring vessels, and each giving off a long 

 spiral excretory duct, which, passing through the dermis, between the pa- 

 pillae, finally opens upon one of the ridges into which the surface of the 

 epidermis is wrought. These glandules secrete the fluid of the perspiration 

 from the blood, and their secretion, after traversing the spiral duct, is 

 eliminated in successive drops, upon the surface. So delicate is this con- 

 trivance, that M. M. Breschet and De V^auzeme inform us that a little 

 valvular fold of epidermis may be seen to be elevated, before the appear- 

 ance of each drop. Such are the exhalunts. 



The inhalants or absorbents do not consist, like the last, of a single tube, 

 but arise, by a multitude of minute vessels, from the lower layer of the 

 epidermis, upon the surface of which their orifices have not as yet been 

 observed. These ramifications collect together into a common trunk, which, 

 passing through the dermis, is supposed to fall into a vein. How absorption 

 is carried on through the epidermis, or whether there be not certain per- 

 forations in that membrane, is not at present known ; and the termination 

 of these absorbents in veins is only rendered highly probable from analogy, 

 and from the fact that injections have actually been made to pass through 

 the cutaneous structure, from the 1,-itter into the former. 



Besides these exhalants and inhalants is found a third system of vessels, 

 Said to be for the purpose of secreting tlie pigment, or colouring matter of 

 the skin. These arise in bulbs, lying between the papillae, and connected, 

 like the former, with thu blood-vessels beneath. Their excretory ducts are 

 straighter than t!ie others, and terminate on the surface of the dermis : the 

 existence of these rests upon the authority above cited, and is, if correctly 

 stated, a discovery of great importance. 



The matter secreted by them is styled the pigment, or paint. 



The pigment is the colouring matter of the skin, being black in the 

 negro, yellow in the copt, swarthy or copper-coloured in the mulatto, and 

 so on. In the inhabitants of the temperate zones the secretion is colour- 

 less, or nearly so. 



