796 URINE. 



TURIA). 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-casts and smaller 

 or larger blood-clots. 



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

 solved blood-coloring matters, haemoglobin, or, and indeed quite often, 

 methsemoglobin (H^EMOGLOBINURIA). The blood-pigments appear in the 

 urine under different conditions, as in dissolution of blood in poisoning 

 with arseniuretted hydrogen, chlorates, etc., after serious burns, after 

 transfusion of blood, and also in the periodic appearance of hsemoglo- 

 binuria with fever. In haemoglobinuria the urine may also have an abun- 

 dant grayish-brown sediment rich in proteid 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, the spec- 

 troscope, the guaiac test, and HELLER'S or HELLER-TEICHMANN'S test. 



Microscopic Investigation. The blood-corpuscles may remain undis- 

 solved for a long time in acid urine; in alkaline urine, on the contrary, 

 they are easily changed and dissolved. They often appear entirely 

 unchanged in the sediment; in some cases they are distended and in 

 others unequally pointed or jagged like a thorn-apple. In hemorrhage of 

 the kidneys a cylindrical clot is sometimes found in the sediment which is 

 covered with numerous red blood-corpuscles, forming casts of the urinary 

 passages. These formations are called blood-casts. 



The spectroscopic investigation is naturally of very great value; and if 

 it be necessary to determine not only the presence but also the kind of 

 coloring-matter, this method is indispensable. In regard to the optical 

 behavior of the various blood-pigments we must refer to Chapter V. 



Guaiac Test. Mix in a test-tube equal volumes of tincture of 

 guaiac and old turpentine which has become strongly ozonized by the 

 action of air under the influence of light. To this mixture, which must 

 not have the slightest blue color, add the urine to be tested. In the 

 presence of blood or blood-pigments, first a bluish-green and then a beau- 

 tiful blue ring appears where the two liquids meet. On shaking the mixture 

 it becomes more or less blue. Normal urine or one containing proteid 

 does not give this reaction. According to LIEBERMANN l this reaction 

 is brought about by the blood pigments acting as catalyst upon the 

 organic peroxides existing in the turpentine, accelerating the decomposi- 

 tion of these and the active oxygen taken up by the guaiaconic acid 

 which is oxidized to guaiac blue (guaiaconic acid ozonide). Urine con- 



1 Pfliiger's Arch., 104. 



