204 



The Mickoscope. 



going this change will be found to be swarming with these organ- 

 isms. The experiments of Sternberg have proven that they are 

 the cause of this change. He found that urine collected in steril- 

 ized vessels, and carefully protected from the invasion of microbes, 

 remained perfectly fresh for indefinite periods. 



The ammonia produced by the decomposition causes the pre- 

 cipitation of compounds which, while they remain in solution in 

 normal acid urine, immediately precipitate and appear as a sedi- 

 ment when the urine becomes alkaline. The compounds insoluble 

 in alkaline urine are calcium phosphate, amorphous or rarely 

 crystalline, acid ammonium urate in spiculated spheres, and the 

 large prismatic crystals of ammonio-magnesian phosphate. This 

 last compound does not exist as such in urine, but is formed by the 

 ammonia combining with the magnesium phosphate to form the 

 double salt. 



In determining the clinical signification of urinary deposits, 

 the observer should always bear in mind the influence of these 

 fermentations. 



CLASSIFICATION OF DEPOSITS. 



Urinary deposits may be classified as follows : 



UNORGANIZED. 



CRYSTALLINE. 



AMORPHOU!- 



Urates - 



Uric acid. 



Calcium oxalate. 



Cystin. 



Hippuric acid. 



Calciiim phosphate. 



Leucin. 



Tyrosin. 



Ammonio-magnesian phosphate. 



Ammonium urate. 



Sodium. 

 i Potassium. 

 Calcium phosphate. 

 Calcium carbonate. 

 Fatty particles. 

 Molecular debris. 



MORE OR LESS ROUNDED IN FORM. 



ORGANIZED. 



CYLINDRICAL IN FORM. 



Blood Corpuscles. 



Pus 



Epithelial cells. 



Spermatozoa. 



Elements of morbid growths. 



Spores and fungi. 



Tube casts. 

 Bacteria. 



Fibrin clots. 



Mucus. 



Masses of bacteria. 



