566 



THE URINE. 



[CH. xxxvu. 



Deposit of calcium carbonate, CaC0 3 , appears but rarely as 

 whitish balls or biscuit-shaped bodies. It is commoner in the 

 urine of herbivora. It dissolves in acetic or hydrochloric acid, 

 with effervescence. 



The following is a summary of the chemical sediments that 

 may occur in urine : 



CHEMICAL SEDIMENTS IN URINE. 



IN ACID URINE. 



Uric Acid. Whetstone, dumb- 

 bell, or sheaf-like aggregations of 

 crystals deeply tinged by pigment. 



Urates. Generally amorphous. 

 The acid urate of sodium and of 

 ammonium may sometimes occur in 

 star-shaped clusters of needles or 

 spheroidal clumps with projecting 

 spines. Tinged brick-red. Soluble 

 on warming. 



Calcium Oxalate. Octahedra, so- 

 called envelope crystals. Insoluble 

 in acetic acid. 



Cystin. Hexagonal plates. Rare. 



Leucine and Tyrosine. Rare. 



Calcium Phosphate, 



CaHPO 4 + 2H 2 0. Rare. 



IN ALKALINE URINE. 



Phosphates. Calcium phosphate, 

 Ca 3 (PO 4 ). 2 . Amorphous. 



Triple phosphate. 



MgNH 4 P0 4 + 6H 2 0. Coffin-lids or 

 feathery stars. 



Calcium hydrogen phosphate. 

 CaHP0 4 . Rosettes, spherules, or 

 dumb-bells. 



Magnesium phosphate, 

 Mg 3 ( P0 4 ) 2 + 22H 2 0. Long plates. 



All soluble in acetic acid without 

 effervescence. 



Calcium Carbonate, CaC0 3 . 

 Biscuit-shaped crystals. Soluble in 

 acetic acid with effervescence. 



Am Dwni n m Urate, 

 C 5 H 2 (NH 4 ) 2 .N 4 8 . " Thorn-apple " 

 spherules. 



Leucine and Tyrosine. Very rare. 



PATHOLOGICAL URINE. 



Under this head we shall briefly consider only those abnormal 

 constituents which are most frequently met with. 



Proteids. There is no proteid matter in normal urine,* and 

 the most common cause of the appearance of albumin in the 

 urine is disease of the kidney (Bright's disease). The term 

 "albumin" is the one used by clinical observers. Properly 

 speaking, it is a mixture of serum albumin and serum globulin. 

 The best methods of testing for and estimating the albiimin are 

 the following : 



(a) Boil the top of a long column of urine in a test-tube. If the urine is 

 acid, the albumin is coagulated. If the quantity of albumin is small, the 

 cloudiness produced is readily seen, as the unboiled urine below it is clear. 

 This is insoluble in a few drops of acetic acid, and so may be distinguished 

 from phosphates. If the urine is alkaline, it should be first rendered acid 

 with a little dilute acetic acid. 



* This absolute statement is true for all practical purposes. Jlorner, 

 however, has recently stated that a trace of proteid matter (serum albumin 

 plus the proteid constituent of mucin) does occur in normal urine ; but the 

 trace is negligeable. many hundreds of litres of urine having to be used to 

 obtain an appreciable quantity. 



