XVI.] 



THE URINE. 



105 



2. Quantity. — Normal. — About 2 J pints (50 ounces) or 150c 

 cc. in twenty-four hours, although there may be a considerable 

 variation even in health, the quantity being regulated by the 

 amount of fluid taken, and controlled by the state of the tissues, 

 the pulmonary and cutaneous excretions. 



Collection. — It should be collected in a tall graduated glass 

 cylinder of a capacity of 2500 cc. with a ground glass top to 

 exclude impurities. Samples of the mixed urine of 

 the 24 hours are used for examination. 



.._ lOOft 

 101D 



.._ 10«0 

 ._1080 

 _1040 



Increastd by drinking water {u.rina potns) or diuretics ; when 

 the skin is cool, its blood-vessels are contracted, and the cutaneous 

 secretion is less active ; after a paroxysm of hysteria, and some 

 convulsive nervous diseases ; in diabetes imipidus and d. inellUus; 

 some cases of hypertrophy ot the left ventricle, and some kidney 

 diseases. The increase may be temporary or persistent, the 

 former as the effect of cold, diuretics, or nervous excitement ; 

 the latter in diabetes and certain forms of kidney-disease. 



Diminished after profuse sweating, diarrhoea ; early stage of 

 acute Bright's disease ; some forms of Bright's disease , the 

 last stages of all forms of Bright's disease ; in general dropsies ; 

 in acute febrile and inflammatory diseases. 



3. Colour. — Normal. — Light-straw to amber-coloured, ^--g^ 

 The colour varies greatly even in health, and is due 'i!!i «( 

 to the presence of a mixture of pigments, probably I ■! 

 largely derived from the decomposition of haemoglobin, j ;: 

 Of these pigments urobilin, an iron-free derivative of * "' 

 Hb, is the chief. The colour largely depends on the 

 degree of dilution of the urine pigments. 



Pale after copious drinking, in diabetes, anaemia, and chlorosis; 

 after paroxysmal nervous attacks (hysteria). N.B. —Pale urines 

 indicate the absence of fever. 



High-coloured after severe sweating, violent muscular exercise, 

 diarrhoea, or during febrile conditions. 



Pathological pigments, purpurine or uro-erythrine in febrile 

 disorders ; bile pigments ; blood. > 



Medicinal Siolistances. — Creosote and carbolic acid make urine 

 nearly black. This is due not to carbolic acid, but to hydro- 

 chinon. Sometimes these urines become almost black on stand- 

 ing exposed to the air. Rhubarb (gamboge-yellow) ; senna 

 (brownish). 



Fio. 52. 



4. Specific Gravity. — Normal^ s.g. 1020 (1015- urinometer. 

 1025). — This is taken by means of the urinometer 



(fig. 52). The instrument ought to be tested by placing it in a 

 cylindrical vessel filled with distilled water to ascertain that its 

 zero is correct. 



(a.) Fill a tall cylindrical vessel with urine, and place the 



