292 THE .URINE. 



variously decussated, and surrounding the bladder. * These are 

 called the detrusor urinae : the fibres which imperfectly sur- 

 round the neck, and are inconstant in origin and figure, have 

 received the appellation of sphincter. 



" The cellular chiefly imparts tone to this membranous viscus. 



" The interior, abounding in cribriform follicles m , is lined 

 with mucus, principally about the cervix. 



" The urine conveyed to the bladder gradually becomes un- 

 pleasant by its quantity, and urges us to discharge it. For this 

 purpose the urethra is given, which " is a canal beginning at the 

 lowest part of the bladder, much longer in the male than the 

 female, and attached to the arch of the pubes by muscular fibres 

 that are described by Mr. Wilson under the name of compressor 

 urethrae and conceived to act as the sphincter of the bladder, 

 " varies with the sex, and will be farther considered in our 

 account of the sexual functions. 



" The bladder is evacuated from the constriction of the sphinc- 

 ter being overcome both by the action of the detrusor and by 

 the pressure of the abdomen." The assistance of the abdominal 

 muscles, however, is not absolutely requisite, however greatly it 

 may contribute ; because, if we keep^them motionless, and direct 

 our attention to the bladder, when it contains urine, a sensation 

 is immediately felt at its neck ; and if we still fix our attention, 

 we can will the passage of the urine through it, probably by 

 willing a relaxation of the muscular fibres of the part, as much 

 as by willing a contraction of the detrusores fibres, the dia- 

 phragm and abdominal muscles being still preserved motionless. 

 " The last drops of urine remaining in the bulb of the" male 

 " urethra are sent forth by the ejaculatores seminis. 



" The nature of the urine varies infinitely n from age, season 

 of the year, and especially from the length of the period since 

 food or drink was last taken, and also from the quality of the 



1 " Santonin's posthumous tables, xv." 

 "" m Fi or- Caldani, Opus. anat. Patav. 1803. 4to. p. 4.'* 



" " See Halle, Mem. de la Soc. de Medecine, vol. iii. p. 469. sq." 

 " The specific quality of some ingesta manifest themselves in the urine so 

 suddenly, even while blood drawn from a vein discovers no sign of their presence, 

 that philologists have thought there must be some secret ways leading directly 

 from the alimentary canal to the kidneys, besides the common channels. An 

 examination of them will be found in Aug. H. L. Westrumb's Commentary 

 (honoured with the royal prize) de phenomenis, quce ad vias sic dictas lotii clan- 

 destinas demonstrandas referuntur. Getting. 1819. 4to., and P. G. C. E. Bark- 



