45^ PHYSIOLOGICAL CHEMISTRY 



ical glass 12-24 hours before sufficient sediment can be secured for the 

 microscopical examination. 



(a) Unorganized Sediments 



Ammonium magnesium phosphate ("triple phosphate"). 



Calcium oxalate. 



Calcium carbonate. 



Calcium phosphate. 



Calcium sulphate. 



Uric acid. 



Urates. 



Cystine. 



Cholesterol. 



Hippuric acid. 



Leucine (?) and tyrosine. 



Hematoidin and bilirubin. 



Magnesium phosphate. 



Indigo. 



Xan thine. 



Melanin. 



Ammonium Magnesium Phosphate ("Triple Phosphate"). 

 Crystals of "triple phosphate" are a characteristic constituent of the 

 sediment when alkaline fermentation of the urine has taken place 

 either before or after being voided. They may even be detected in 

 amphoteric or slightly acid urine provided the ammonium salts are 

 present in large enough quantity. This substance may occur in the 

 sediment in two forms, i.e., prisms and the feathery type. The pris- 

 matic form of crystals (Fig. 129, page 408) is the one most commonly 

 observed in the sediment; the feathery form (Fig. 129, page 408) pre- 

 dominates when the urine is made ammoniacal with ammonia. 



The sediment of the urine in such disorders as are accompanied by 

 a retention of urine in the lower urinary tract contains "triple phos- 

 phate" crystals as a characteristic constituent. The crystals are fre- 

 quently abundant in the sediment during paraplegia, chronic cystitis, 

 enlarged prostate, and chronic pyelitis. 



Calcium Oxalate. Calcium oxalate is found in the urine in the 

 form of at least two distinct types of crystals, i.e., the dumb-bell type 

 and the octahedral type (Fig. 134, page 459). Either form may occur 

 in the sediment of neutral, alkaline, or acid urine, but both forms are 

 found most frequently in urine having an acid reaction. Occasionally, 

 in alkaline urine, the octahedral form is confounded with "triple phos- 



