ORGANS OF THE BODY. 607 



The thickish fatty nature of the secretion of the axillary glands hardly 

 warrants the application to them of the term "sudorific" with any 

 degree of propriety ; they require some special name just as much as the 

 glands of the external ear. 



Eeceritly a ring of very large sweat glands, lined with columnar epithe- 

 lium, has been described as surrounding the opening of the anus by A. 

 Gay, by whom they are named the ".circumanal glands" 



The glandules ceruminosce, closely crowded together, are seated in 

 the cartilaginous portion of the external auditory meatus. They present 

 the same structure as the ordinary sweat glands, with convolutions of 

 G'23-1'69 mm. in diameter, but differ from them in possessing short, 

 almost straight and never spiral, excretory ducts. The gland-cells of the 

 convoluted portion contain granules and drops of fatty matters with 

 molecules of a brownish pigment, which communicate to the secretion its 

 well-known colour. 



The cerumen auris, a yellowish, thick, and bitter substance, presents 

 under the microscope, beside epidermal scales, granules and globules of 

 an ordinary yellow fat, molecules of a brown pigment just mentioned 

 (either separate or aggregated), and large cells filled with oil globules, 

 which in the opinion of Koelliker may be derived from the sebaceous 

 glands of the neighbourhood. 



According to an analysis of Berzelius, the cerumen of the ear contains, 

 besides epidermal scales, a soft fat, a yellowish substance soluble in 

 alcohol, and bitter to the taste, but which has nothing to do with the 

 constituents of bile (Lehmann), extractive matters, potash, and lime salts. 

 Petrequin found also a potash soap here. In fact, potash is almost the 

 only alkali present in the cerumen ; only traces of soda and lime are to be 

 found. 



303. 



Part of the water contained in the skin is continually exuding through 

 the hard, dry, epidermal scales over the whole surface of the human 

 body. This process, which, although varying in intensity at times, may 

 nevertheless be regarded as a constant one, is known as perspiration. 

 The sources of this moisture are in the first place the blood-vessels of the 

 papillae, and the transuded tissue fluid of the latter, and then the aqueous 

 contents of the passages of the sweat glands, which also exhale fluid from 

 their surface. How much is to be set down to these sources respectively 

 is still a matter of doubt. According to C. Krause the largest proportion 

 by far is derived from the bodies of the papillae. We are indebted to 

 this observer for the discovery that horny epidermis is almost impervious 

 to water in such a condition that it will form drops, but permeable to all 



In contrast to this constant and purely physical process of evaporation 

 of the water of the skin, there is another, which is only periodically active, 

 namely, the generation of sweat, the efflux of water in the condition of 

 drops from the innumerable orifices of the sudorific glands, in which the 

 small isolated globules form by confluence larger drops upon the greasy 

 surface of the skin. Both processes, however, are frequently merged into 

 one another. 



The amount of water which the body loses through the skin varies 

 naturally at different periods. It may be estimated, according to Krause, 

 at from 8 to 9 hundred grammes per diem on an average, with extremes 



