194 Veterinary Medicine. 



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

 splanchnic nerve. This last is, however, much 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 transverse 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 pressure 

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

 blood elsewhere. This influence of the nervous system 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. 



PHYSICAIv 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. Bxtraneous 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, crealinin, acetone, oxalic acid, allautoin, xanthiu, hypoxanthin, 

 cyauuric acid, leucin, 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 yellow, yellowish red, and red. 



