CH. XXXIX.] BILE, BLOOD, AND PUS IN UEINE 603 



salts. If some ilowers of sulphur are sprinkled on the surface of 

 normal urine, it remains floating on the top. If bile salts are present 

 even in small quantities, the fine sulphur particles fall down to the 

 bottom of the vessel in which the urine is contained ; this is due to 

 an alteration of surface tension which bile salts produce. 



Blood. When haemorrhage occurs in any part of the urinary 

 tract, blood appears in the urine. It is found in the acute stage of 

 Bright's disease. If a large quantity is present, the urine is deep 

 red. Microscopic examination then reveals the presence of blood - 

 corpuscles, and on spectroscopic examination the bands of oxyhaemo- 

 globin are seen. 



If only a small quantity of blood is present, the secretion 

 especially if acid has a characteristic reddish-brown colour, which 

 physicians term " smoky." 



The blood pigment may, under certain circumstances, appear in 

 the urine without the presence of any blood-corpuscles at all. This 

 is produced by a disintegration of the corpuscles occurring in the 

 circulation. The condition so produced is called hcemogldbinuria ; 

 it occurs in several pathological states, as for instance in the tropical 

 disease called "Black-water fever." The pigment is in the condi- 

 tion of methaemoglobin mixed with more or less oxyhaemoglobin, and 

 the spectroscope is the means used for identifying these substances. 



Pus occurs in the urine as the result of suppuration in any part 

 of the urinary tract. It forms a white sediment resembling that of 

 phosphates, and, indeed, is always mixed with phosphates. The pus 

 corpuscles may, however, be seen with the microscope ; their nuclei 

 are rendered evident by treatment with 1 per cent, acetic acid, and 

 the pus-corpuscles are seen to resemble white blood-corpuscles, which, 

 in fact, they are in origin. They dissolve in glacial acetic acid. 



Some of the protein constituents of the pus cells and the same 

 is true for blood pass into solution in the urine, so that the urine 

 pipetted off from the surface of the deposit gives the tests for protein. 



On the addition of liquor potassae to the deposit of pus cells, a 

 ropy gelatinous mass is obtained. This is distinctive. Mucus treated 

 in the same way is dissolved. 



Amino-acids. Normal urine contains traces of glycine. Leucine, 

 tyrosine, and other amino-acids may be present after extensive dis- 

 integration of tissue protein, such as occurs in acute atrophy of the 

 liver (p. 586). Cystine may occur as a rare anomaly of metabolism 

 (p. 599). Associated with cystinuria one often finds diaminuria, 

 that is, the passage of diamines into the urine ; these are known as 

 cadaverine (C 5 H 14 N 2 ) and putrescine (C 4 H 1: >N 2 ), and are the result of 

 the removal of CO 2 from the diamino-acids lysine and 01 nithine respect- 

 ively. Homogentisic acid, found in alcaptonuria (see preceding page), 

 is another somewhat similar anomaly ; it arises from tyrosine. 



