THE URINE. 401 



amount of albumin in the urine; This method is claimed to give 

 very good results. A special description accompanies each ap- 

 paratus. 



The method proposed by ROBERTS and STOLNIKOW and further developed 

 by BRANDBERG, though somewhat more difficult to perform, also gives satis- 

 factory results. The density methods of LANG, HUPPERT, and ZAHOR are 

 also very good. The last consists in determining the specific gravity before 

 and after the coagulation of the albumins. 



Mucin occurs in the urine under normal conditions partly dissolved and 

 partly in a strongly-distended, finely-divided state. It appears in greatest 

 amounts in catarrhal affections of the urinary passages. The occurrence of 

 pure mucin in the urine has thus far not been positively shown. 



To detect mucin in urine first dilute with water, partly to prevent the pre- 

 cipitation of uric acid on the subsequent addition of acid, and partly to 

 diminish the solubility of the mucin in the common salt of the urine. Now 

 add an excess of acetic acid. The precipitate formed is purified by dissolving 

 in water with the addition of a little alkali and reprecipitated with acetic acid. 

 The precipitate is tested with the ordinary mucin reagents. To avoid mistak- 

 ing mucin for nucleoalbumin, which is similar to mucin, the precipitate must 

 be tested in regard to its behavior on boiling with dilute mineral acids. If no 

 reducible substance is formed by this treatment, it contains no mucin. 



Blood and Blood-coloring Matters. The urine may contain 

 blood from hemorrhage in the kidneys or other parts of the urinary 

 passages (HJEMATUKIA). In these cases, when the quantity of blood 

 is not very small, the urine is more or less cloudy and colored 

 reddish, yellowish red, dirty red, brownish red, or dark brown. 

 In recent hemorrhages, in which the blood has not decomposed, 

 the color is nearer blood-red. Blood-corpuscles may be found in 

 the sediment, sometimes also blood-cylinders and smaller or larger 

 blood -clots. 



In certain cases the urine contains no blood-corpuscles, but only 

 dissolved blood-coloring matters, haemoglobin, or, and indeed quite 

 often, methaemoglobin (H^MOGLOBINTTRIA). The blood-coloring 

 matters appear in the urine under different conditions, as in dissolu- 

 tion of blood in poisoning with arseniuretted hydrogen, chlorates, 

 etc., after serious burns, after transfusion of blood, and also in the 

 periodic appearance of haemoglobinuria with fever. The urine may 

 in haemoglobinuria also have an abundant grayish-brown sediment 

 rich in albumin which contains the remains of the stromata of 

 the red blood-corpuscles. In animals haemoglobinuria may be 

 produced by many causes which force free haemoglobin into the 

 plasma. 



To detect blood in the urine we make use of the microscope, 



