COMPOSITION AND CHARACTERS OF URINE 1253 



in the form of alkaline heematoporphyrin and gives the characteristic 

 absorption bands of the latter. 



Urorosein is a name that has been given to a pigment which is 

 formed when the urine is treated with strong mineral acids. It is 

 probably an indol derivative. It gives a single absorption band 

 between the lines D and E. 



ABNORMAL CONSTITUENTS OF THE URINE 



A very large number of substances occur in the urine in minute 

 traces and may be detected when large quantities of this fluid are 

 worked up at one time. Most of the so-called pathological con- 

 stituents may be detected in this way in normal urine. It is only 

 when they occur in easily detectable amounts that their presence 

 becomes of any significance. 



COAGULABLE PROTEIN. Under normal circumstances urine is 

 free from any coagulable protein except the small traces of mucinous 

 material, nucleoprotein, which gives the cloudiness to the urine. If 

 the kidney-cells are damaged by disease, by interference with their 

 blood-supply, or by circulating poisons, the glomerular epithelium 

 permits the passage of a certain amount of the proteins of the plasma. 

 Under these circumstances, if small pieces of the kidney be plunged 

 into boiling water, the coagulated protein may be seen in Bowman's 

 capsule. The presence of coagulable protein (generally spoken of as 

 albumen) in the urine is significant of the pathological conditions 

 of the kidney associated with Bright's disease. A small trace 

 will generally be found in the urine which is passed shortly after 

 taking muscular exercise. Under this condition the presence of 

 albumen in the urine has no pathognomic significance. 



The proteins generally found are identical with those of the blood- 

 plasma and consist of serum albumen and serum globulin. Their 

 presence in the urine may be detected by the precipitate produced on 

 boiling. In carrying out this test a few cubic centimetres of saturated 

 salt solution should be added and one or two drops of dilute acetic 

 acid. A more delicate test is that known as Heller's. Some strong 

 nitric acid is placed in a test-tube and the urine is poured carefully 

 down the side of the tube so as to form a layer on the surface of the 

 nitric acid. If albumen be present a white ring is formed at the 

 junction of the two liquids. 



SUGAR. Normal urine contains about one part per thousand of 

 glucose. In diabetes the power of assimilating carbohydrates is 

 diminished or destroyed. The amount of sugar in the blood is 

 increased, and sugar appears in large quantities in the urine. The sugar 

 is practically always glucose or dextrose. Lactose may occur in the 

 urine of nursing women even in conditions of health. Since both 



