SEDIMENTS. 



UNORGANIZED. 



Separating from a urine which is acid in reaction, the fol- 

 lowing sediments may be present : 



1. CRYSTALLINE TYPE.* 



(a) Uric Acid, Color, golden brown. To what is this 

 due? Does not dissolve upon warming. Soluble in NaOH 

 and re precipitated by HC1. Responds to the murexide 

 test. Very characteristic crystalline form under the micro- 

 scope. 



(6) Calcium Oxalate. Usually present mixed with uric 

 acid. Colorless. Dissolves easily in HC1, but is insoluble in 

 acetic acid. (See Triple Phosphate, with which there is the 

 possibility of confusion.) Under the microscope the crystals 

 are transparent, refractive, octahedral (envelope shape). 



(c) Bilirubin and Hcematoidin. The former crystallizes in 

 golden or brown rhombic plates or needles. Dissolves easily 

 in alkalies and chloroform and gives Gmelin's reaction. The 

 latter is similar in crystalline form, but does not dissolve 

 in alkali and gives a blue coloration with HN0 3 . 



(d) Cystine. Under the microscope it appears as super- 

 imposed six-sided plates, which are insoluble in acetic acid, 

 but soluble in NEUOH (differing from uric acid). 



(e) Tyrosine, Leucine, and Xanthine. Very rare. For 

 teste see under these substances. 



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