DISEASES OF THE URINARY ORGANS. 



By JAMES LAW, F. R. C. V. S., 



Professor of Veterinary Science, etc., in Cornell University, 



The urinary organs constitute tlie main channel through which are 

 excreted the nitrogenous or albuminoid principles, whether derived di- 

 rectly from the food or from the muscular and other uitrogenized tissues 

 of the body. They constitute, besides, the channel through which are 

 thrown out most of the poisons, whether taken in by the mouth or skin 

 or developed in connection with faulty or natural digestion, blood- 

 forming, nutrition, or tissue destruction; or, finally, poisons that are 

 developed within the body as the result of normal cell-life or of the life 

 of bacteria or other germs that have entered the body from without. To 

 a large extent, therefore, these organs are the sanitary scavengers and 

 purifiers of the system, and when their functions are impaired or ar- 

 rested the retained poisons quickly show their presence in resulting 

 disorders of the skin and connective tissue beneath it, of the nervous 

 system, or other organs. Nor is this influence one-sided. Scarcely an 

 important organ of the body can suffer derangement without entailing 

 a corresponding disorder of the urinary system. Nothing can be more 

 striking than the mutual balance maintained between the liquid secre- 

 tions of the skin and kidneys during hot and cold weather. In sum- 

 mer, when so much liquid exhales through the skin as sweat, compar- 

 atively little urine is passed, whereas in winter, when the skin is inact- 

 ive, the urine is correspondingly increased. This vicarious action of 

 skin and kidneys is usually kept within the limits of health, but at 

 times the draining otf of the water by the skin leaves too little to keep 

 the solids of the urine safely in solution, and these are liable to crys- 

 tallize out and form stone and gravel. Similarly the passage in the 

 sweat of some of the solids that normally leave the body, dissolved in 

 the urine, serves to irritate the skin and produce troublesome eruptions. 

 A disordered liver contributes to the production, under different cir- 

 cumstances, of an excess of biliary coloring-matter, which stains the 

 urine; of an excess of hippuric acid and allied products, which, being 

 less soluble than urea (the normal product of tissue change), favor the 

 forniatiou of stone, of taurocholic acid, and other bodies that tend, when 



59 



