GLANDERS. CONSTRUCTION OF THE BLADDER, 53 



i>f it to chemical analysis in order to decide that point. "The result was, ih?t 

 it contains an unusually large })roportion of that principle, so that without be 

 iiiiT concentrated by evaporation, it yielded crystals of nitrate of urea, very 

 readily on the addition of nitric acid." This fact being thus satisfactorily as- 

 certained, accounts for the strong ammoniacal vapour of stables that affects the 

 eyes of the attendants, and being inhaled (as said in sect. 39.), is clearly the 

 harbinger of several diseases in the horses confined in them — glanders among 

 the rest. 



56. Thk Bladder, or receptacle for the redundant water of the whole sys- 

 tem, as it is separated from the blood by the kidneys, is situated within the 

 hollow of the pelvis, at tlie intersection of H 1 with 33, 34 on the plate of a 



skeleton, with its outlet or neck turned towards the place of 

 exit, varying a little according to the sex. It consists of three 

 coats or layers, the outer two being muscular, and having 

 their fibres crossing each other — (as may be seen upon split- 

 ting asunder a stale bladder), the better to enable it to contract 

 upon and expel its contents. The inner coat is membrane- 

 ous, sensible on distention, and secreting a mucous fluid to 

 protect itself against the elfects of the urine. When, how- 

 ever, the bladder becomes full, the secretion is insufficient foi 

 its protection, and irritation commences in order to induce the 

 muscular coats to concur in the expulsion of the urine. This 

 desire must be very great in the horse, for the reason assigned 

 at the close of the preceding section, and shows the necessity 

 of permitting him to void his urine upon his first intimating an incHnation 

 thereto. The shape of some horses' bladders differs a good deal from that of 

 others, — particularly about the neck, those of the female being considerably 

 wider, and shorter, than those of the male, a circumstance to be remembered 

 when I come to treat of the disorders incident thereto ; since in inflammation 

 of its neck, for example, in one sex we are obliged to have recourse to instru- 

 ments, in the other the urine may be discharged by the fingers. But it so 

 happens that horses are more liable to the disorder just named than mares. 

 My reader will also please to note, that the thin membrane which defends the 

 whole intestine against the friction of the surface, (termed peritonajum,) reaches 

 backward to only half way over the bladder; so that it offers no obstruction to 

 our operations upon its neck in cases of disease. 



57. To recur once more to the subject of a preceding section (the 55th)— 

 the principle (of urea) that resides in any given quantity of urine evacuated 

 by the horse, it may be here observed, that when the animal, on a journey, 

 has been pushed onward, and thus prevented from staling for a considerable 

 time, he at length produces it of a deeper colour and less in quantity than 

 usual, a change which has been effected by the great heat of his body having 

 taken it up again, by the absorption and effusion which nature has provided, 

 of aqueous particles from one part of the system to another. The principlcj 

 or urea, however, remains in the bladder, and produces one of two evils; either 

 the inner or sensible coat becomes inflamed, and loses, after an attack of dia- 

 betes, some part of its function of secreting the mucous fluid for its defence, 

 if it does not terminate fatally; or, being less severe, but often repeated, a de- 



*c complain. Whatever practitioner should undertake to judge of the horse's diseases by it« 

 urine, must prepare himself to undergo a good deal of ridicule, and may expect some calumny ; 

 he would not, however, be far from the ri'glit path towanis making a proper estimate of th» 

 quantitj or violence of its ailment, though lie might not so readily ascertain the precise nature 

 rf the disorder. The terms "nephrin," and "uric acid," the oldest and the newest forth^ 

 principle of this evacuation, show the assiduity of which it has lieen dieu'ed worthy, in tha* 

 practice where it is confessedly of less importance than it is in ours. 



