THE SEBACEOUS ORGANS. 341 



water in which we bathe to assemble in drops, on the surface 

 of the body, rather than to wet it uniformly. This humour 

 produces a rancid disagreeable smell in negroes, and such per- 

 sons as do not resort to ablutions of the whole skin, from time 

 to time. It is particularly abundant about the places provided 

 with hairs, as the scalp, the genital organs, the axillce, and 

 seems to be intended to maintain the flexibility and smoothness 

 of the skin and hair, and to prevent the former from chapping. 

 These qualities of it are possessed, in a considerable degree, 

 by the oily articles of the toilet, which are used for the same 

 purpose. There can be no doubt of the unctuous quality of 

 this secretion, as, when collected on a piece of clothing or on 

 blotting-paper, it burns with a white .flame. Its quantity is 

 readily augmented by certain kinds of clothing, which most 

 persons must have observed shortly after putting on a flannel 

 shirt next to the skin. 



It is sufficiently certain that the apparatus producing this oil 

 is not visible to the naked eye in most parts of the skin, so that 

 there would seem to be a necessity of accounting for its ap- 

 pearance there, in some other way besides a distinct glandular 

 apparatus. Bichat considered it to arise from a set of exha- 

 lents differing from those which secrete the matter of perspira- 

 tion, a theory far more rational than that which attributes it to 

 the percolation of the subcutaneous fatty matter. M. Beclard, 

 however, admits that sebaceous follicles exist over the whole 

 surface of the skin, with the exception of the palms and 

 soles; because the skin is universally rendered unctuous by this 

 discharge: many follicles exist, which are only visible to the 

 microscope; and because morbid changes frequently render 

 them evident, where their existence was not suspected before- 

 In many places these follicles are sufficiently obvious and very 

 numerous, as on the nose, about the corners of the mouth, on 

 the ear and behind it, and on the face, generally, of some indi- 

 viduals. When the skin has been injected, they are found to 

 consist of small pouches placed in its thickness and having 

 their parietes abundantly furnished with blood vessels. 



The discharge from them sometimes becomes inspissated, and 

 does not readily pass through their orifices; in which case, con- 

 tinuing to accumulate, it will, finally, form a sensible tumour. 

 Most frequently it does not collect to such an exten% but is 



