192 Veierina?y Medicine. 



just in front of the origin of the vagus and from section of the 

 splanchnic nerve. This last is, however, nuich less marked and 

 more transient than from section of the renal nerve noted above ; 

 the latter causing dilation of the renal vessels only, and increased 

 pressure, whereas the former causes dilation of the abdominal 

 organs generally, diverting the blood largely to other parts than the 

 kidney and preventing the same increase of pressure in the vessels 

 of the latter. For the same reason transver.se section of the medulla 

 oblongata, or of the .spinal cord as far back as the seventh cervical 

 vertebra, lessens or interrupts the urinary secretion, the pre.ssure 

 in the kidney being reduced by the diversion of much of the 

 blood elsewhere. This influence of the nervous sy.stem on the 

 urinary secretion seems to be mainly or entirely one of increase 

 or decrease of blood pressure in the kidney. For this reason a 

 weak heart tends to lessen urinary secretion. 



Excessive increase of urine is only important when con- 

 tinuous and in the absence of visible cause, such as diuretics. 



PHYSICAL PROPERTIES OF THE URINE. 



Color, yellow, red, brown ; horse, ox, calf, sheep, goat, dog, cat, bird. 

 In disease : pale yellow, with water in excess ; deep yellow, red, brown with 

 solids in excess, urobiline, biliverdin, haemoglobin. Extraneous colors. 

 Bilharzia. Translucency : Turbidity : horse, ruminants, carnivora, pig. In 

 disease, horse, other animals. Consistency, viscous, stringy, tarry ; odor, 

 horse, dog, cat, ammoniacal, foetid, drug odor. Specific gravity', estimate of 

 solids ; reaction, acid, alkaline, neutral ; morbid chemical changes, sodium 

 chloride, phosphate, alkaline, earthy, indican, urea, uric acid, hippuric acid, 

 phenol, creatinin, acetone, oxalic acid, allantoin, xanthin, hypoxanthin, 

 cyanuric acid, lencin, albumen, glucose, bile salts and pigments, blood, 

 haemoglobin, epithelium, pus, casts. 



Color. In estimating the color we must note the various 

 shades of yellow, red and brown and compare these with the 

 normal in different genera of animals, on different food and 

 water, and in different conditions of health. Grades of color 

 may be stated as follows : 



Yellow : Pale, clear and deep yellows. 



Red : Reddish j^ellow, yellowish red, and red. 



