ANALYSIS OF THE URINE. 



347 



of a calcium hypochlorite solution ; the indican is transformed into 

 indigo-blue (blue coloration); the indigo- blue may be extracted by 

 means of chloroform, and its quantity determined by the colori- 

 metric method or by means of the scale. 



VI. Chlorides. Normal urine contains chlorides the quantity 

 of which diminishes in certain diseases : in febrile affections and 

 exudative inflammations of the internal organs, particularly in 

 those of the serous membranes ; the proportion of these salts dimin- 

 ishes also in the dropsies of the large splanchnic cavities (the chlo- 

 rides pass in these instances into the transudation products and are 

 consequently less abundant in the urine). The increase of the 

 chlorides of the urine form thus a favorable prognostic symptom in 

 these different morbid states (resorption of the pathological liquids 

 and elimination through the urine). 



The quantitative analysis is practised by subjecting cold urine to 

 the action of nitrate of silver, after having first deprived it of albu- 

 min, and acidulating with nitric acid. The simple comparison of 

 the precipitates (chlorides of silver) obtained for several days suc- 

 cessively, permits us to conclude as to an augmentation or a 

 diminution of chlorides. 



(j5.) Physical Examination of Urine. 



I. Color. In a normal condition, the urine shows various tints, 

 due to diverse and trivial causes. It is very pale in polyuria, sugar 

 diabetes, chronic nephritis, during convalescence from febrile dis- 

 eases, etc.; it is very dark, on the contrary, when its quantity is 

 much reduced during fever ("loaded urine"); it is of an intense 

 yellow in icterus and liver diseases ; it is red in hemoglobinuria 

 and hematuria, after the ingestion of rhubarb, senna, mercurialis 

 annua, and "semen contra" (santonica), etc.; it is dark green in tar 

 and carbolic acid poisonings, after administration of thallin, etc. ; 

 finally it is grayish, of bad appearance, in the septic diseases. 



II. Quantity. It is diminished in diarrhea, in the diseases 

 .accompanied by more or less abundant exudations, in an intense 

 fever or lowering of the blood pressure by weakness of the heart, 

 and in acute nephritis, etc.; it is increased in polyuria, sugar 

 diabetes and diabetes insipidus, renal hyperemia, interstitial chronic 

 nephritis, during a convalescence, in febrile crisis, after the resorp- 

 tion of exudates and transudates, and after the administration of 

 diuretics. 



