EXCRETION 395 



fever, either absolutely or in proportion to the amount of 

 nitrogen in the food. In the interstitial varieties of kidney 

 disease the urea is usually not diminished, but when the 

 stress of the change falls on the tubules (parenchymatous 

 nephritis), it is distinctly decreased it may be even to one- 

 twentieth of the normal. 



Uric acid is diminished in the urine in gout (perhaps to 

 one-ninth of the normal), not only during the paroxysms, 

 but in the intervals. It accumulates in the blood and tissues, 

 and, as sodium urate, may form concretions in the joints, 

 the cartilage of the ear, and other situations. Watson 

 relates the case of a gentleman who used to avail himself of 

 his resources in this respect by scoring the points at cards 

 on the table with his chalky knuckles. In leukaemia the 

 quantity of uric acid and xanthin bases in the urine is 

 greatly increased. 



The aromatic bodies, of which indoxyl may be taken as the 

 type, are increased when the conditions of disease favour 

 the growth of bacteria in the intestine, e.g., in cholera, acute 

 peritonitis, carcinoma of the stomach. A marked increase 

 in the amount of the 'paired ' sulphuric acid in the urine is 

 to be taken as an indication that the bacteria are gaining 

 the upper hand in the intestinal tract; a marked diminution 

 is usually a sign that the battle has begun to turn in favour 

 of the organism (Practical Exercises, p. 423). 



Sugar, proteids, the pigments of bile and blood, or their derivatives, 

 are the most important abnormal substances found in solution in the 

 urine. Toxalbumins produced by bacterial action have also been 

 demonstrated in the urine in certain diseases, as in erysipelas (Brieger 

 and Wassermann). Red blood - corpuscles and leucocytes (pus 

 corpuscles, white blood-corpuscles, mucus corpuscles) are the chief 

 organized deposits ; but spermatozoa may occasionally be found, as 

 well as pathogenic bacteria, e.g., the typhoid bacillus ; and in disease 

 of the kidney casts of the renal tubules are not uncommon. These 

 tube-casts may be composed chiefly of red blood-corpuscles, or of 

 leucocytes, or of the epithelium of the tubules, sometimes fattily 

 degenerated, or of structureless proteid, or of amyloid substance. 

 Abnormal crystalline substances, such as leucin, tyrosin, and cystin, 

 may be on rare occasions found in urinary sediments ; but generally 

 the unorganized deposits of pathological urine consist of bodies 

 actually present in, or obtainable from, the normal secretion, but 

 present in excess, either absolutely, or relatively to the solvent power 

 of the urine. 



