PRACTICAL EXERCISES 



495 



Unorganized Sediments (continued) 



IN ACID URINE. 



ammonium occasionally found 

 in the crystalline form (rosettes 

 of needles). 



Calcium Oxalate. Octahedral, 

 'envelope' crystals, not 

 coloured. Insoluble in acetic 

 acid. Soluble in hydrochloric 

 acid (Fig. 161, p. 438). 



Cysiin. Hexagonal plates. 

 Rare (Fig. 163, p. 439). 



l.eucin and Ty rosin (Figs. 

 169, 170, p. 452). Rare. Also 

 found in alkaline urine, but rarely. 



Triple Phosphate. Sometimes 

 found in weakly acid urine. 



IN ALKALINE URINE. 



rhombic tablets, which are dis- 

 solved at the edges by ammo- 

 nium carbonate solution, unlike 

 triple phosphate. All the above 

 are soluble in acetic acid without 

 effervescence. 



Calcium Carbonate. Small 

 spherical or dumb-bell-shaped 

 bodies soluble in acetic acid with 

 effervescence. 



Ammonium Uraie. Dark 

 balls, often covered with spines. 

 Soluble in acetic or hydrochloric 

 acid, with formation of uric acid 

 crystals (Fig. 165, p. 439). 



4. Specific gravity. 



5. Quantity of urine in twenty-four hours. If the quantity is 

 abnormally large and the specific gravity high, test for sugar. 



6. Inorganic constituents not generally of clinical importance, but 

 in special diseases they should be examined e.g., chlorides in 

 pneumonia. 



7. Normal organic constituents. Sometimes quantitative estima- 

 tion of urea or total nitrogen in fever, and in diabetes and Bright's 

 disease. 



8. Chemical examination for abnormal organic constituents, 

 especially albumin and sugar. 



Albumin. (i) Heat some of the urine in a test-tube to boiling. A 

 precipitate insoluble on addition of a few drops of acetic acid consists 

 of coagulable protein. A precipitate soluble in acetic acid consists 

 of earthy phosphates. 



(2) Heller's test. Put some strong nitric acid in a test-tube and 

 run on to it some urine. A white ring indicates protein. 



A quantitative estimation may be made by the method of Roberts 

 and Stolnikow or Esbach (p. 487). 



Sugar. (i) Trommer's test. (Fehling's solution may be used.) 

 If the result is indecisive : 



(2) Phenyl-hydrazine test (p. 488). 



(3) In case of doubt confirm by yeast test. 



A quantitative estimation may be made with Fehling's solution or 

 the polarimeter. 



