600 



THE URINE 



[CH. XXXIX. 



deposited in acid urine. Pus in urine is apt to be mistaken for 

 phosphates, but can be distinguished by the microscope. 



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. 



Cystine. Hexagonal plates. Rare. 



Leucine and Tyrosine. Rare. 



Calcium Phosphate, 



CaHPO 4 + 2H 2 O. 



IN ALKALINE URINE. 



Phosphates. Calcium phosphate, 

 Ca 3 (PO 4 ) 2 . Amorphous. 



Triple phosphate, 



MgNH 4 PO 4 + 6H 2 O. Coffin-lids or 

 feathery stars. 



Calcium hydrogen phosphate, 

 CaHPO 4 . Rosettes, spherules, or dumb- 

 bells. 



Magnesium phosphate, 

 Mg 3 (PO 4 ) 2 + 22H 2 O. Long plates. 



All the preceding are soluble in acetic 

 acid without effervescence. 



Calcium Carbonate, CaCO 3 . Biscuit- 

 shaped crystals. Soluble in acetic acid 

 with effervescence. 



Ammonium Urate, 



C 5 H 2 (NH 4 ) 2 .N 4 O 3 . " 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. 



Proteins. There is no protein 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. Of these, serum albumin is 

 usually the more abundant. Globulins, and especially euglobulins, 

 have probably larger molecules, so escape of globulin indicates more 

 serious damage to the renal cells. The best methods of testing for 

 and estimating the protein 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 



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

 has stated that a trace of protein (serum albumin phis the protein constituent of 

 mucin) does occur in normal urine ; but the trace is negligible, many hundreds of 

 litres of urine having to be used to obtain an appreciable quantity. 



