344 PHYSIOLOGICAL CHEMISTRY. 



complished by the use of this instrument in a few minutes, and 

 far more perfectly, whereas when the other method is used it is 

 frequently necessary to allow the urine to remain in the conical 

 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. 



Haematoidin and bilirubin. 



Magnesium phosphate. 



Indigo. 



Xanthine. 



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 de- 

 tected 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. y prisms and the 

 feathery type. The prismatic form of crystal (Fig. 96, p. 301) is 

 the one most commonly observed in the sediment; the feathery 

 form (Fig. 96, p. 301) predominates when the urine is made am- 

 moniacal 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 

 phosphate " crystals as a characteristic constituent. The crystals 

 are frequently 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 



