796 



THE URINE. 



diameter or be broadened toward the periphery of the rosette. 

 All these formations are highly refracting and colorless. Their sig- 

 nificance is the same as that of triple phosphates. (See Fig. 364.) 

 (8) Calcium carbonate is the most common sediment in the 

 urine of herbivorous animals, and the turbidity of their urine is 



due to its presence. In man 

 this salt is of infrequent oc- 

 currence appearing, together 

 with the phosphates, in the 

 shape of fine granules or dumb- 

 bells. It is observed, in com- 

 bination with magnesium salts, 

 as delicate prisms. It appears 

 mainly in inflammatory and 

 carious processes of the bony 

 system. The addition of acid 

 produces an effervescence of 

 this salt, as well as of ammo- 

 nium carbonate. (See Fig. 364.) 



Magnesium phosphate is observed 

 in urine after the internal use of the 

 fixed alkali-carbonates, such as are 

 held in solution by many mineral 

 waters. It produces elongated quad- 

 rilateral plates. 



Mucus occurs in varying 

 quantities in normal urine, 

 more especially in the female. It appears as finely striated, 

 scarcely perceptible strings, being a physiological product of 

 the epithelia. Slight irritation of the mucosa by acid urine 

 laden with uric acid and urate of soda, increases the amount 

 of mucus, and, the urates being precipitated on it, the stringy 

 masses become more easily perceptible. They may be mis- 

 taken for casts, as they bear some resemblance to them. Mucus- 

 corpuscles, together with mucus- strings, are also observed, 

 having the character of finely granular, sometimes nucleated, 

 plastids. If sperm is admixed with the urine, its mucous con- 

 stituent appears as pale, caky masses, entangled with sperrnato- 

 zoids. In chronic catarrhal inflammation of the mucosa of the 

 urethra, the mucus-strings, voided from the ducts of the mu- 

 cous glands, are very large, cylindrical, and twisted ; they often 

 are perceptible to the naked eye. The mucus secreted by the pros- 



FIG. 363. TRIPLE PHOSPHATES. 



P, perfectly developed crystals; _pi, imper- 

 fectly developed crystals. Magnified 300 

 diameters. 



