268 PEACTICAL PHYSIOLOGY 



hence called Stellar Phosphates (Fig. 161). The crystalline form may 

 also occur in faintly acid urines. 



(b) Ammonium-Magnesium Phosphate. When urine gets stale and 

 ammonia develops in it, a white sediment and a white surface film 

 form. Under the microscope these are seen to be made up of large 

 clear crystals like " knife rests" or, if excess of ammonia be present, 

 they may look like "feathery stars" This latter type can be easily 

 got by adding ammonia to normal urine (Fig. 162). 



2. Biurate of Ammonia. This looks like the biurate of soda 

 crystals, but is associated with crystals of phosphates, and occurs in an 

 alkaline urine. 



3. Carbonates. In the urine of vegetarians these are not uncommon. 

 The urine effervesces on adding acetic acid. Microscopically the sedi- 

 ment is usually amorphous, but may exist as biscuit-shaped crystals 

 or as dumb-bells (Fig. 159). 



CHAPTER XIX. 



PATHOLOGICAL URINE. 



I. Proteids in the Urine Albuminuria. Traces of mucin or nucleo- 

 albumin may be added to the urine in its passage along the urinary 

 tract, but otherwise, healthy urine does not contain any proteid. Where 

 the kidneys are diseased, however, a certain amount of the plasma 

 proteids leak into the urine, where they can be recognised by certain 

 tests, the condition being called Albuminuria. 



Also when proteids other than serum albumin and globulin gain access 

 to the blood, they are at once excreted into the urine. It is on this 

 account that albuminuria results after the consumption of a large num- 

 ber of raw eggs (egg flip), because the intestinal epithelium allows a 

 certain amount of the unchanged albumin into the blood, where, how- 

 ever, it is foreign (in being egg- and not serum -albumin), and is conse- 

 quently immediately picked out by the kidneys. In disease of the red 

 bone marrow, a body somewhat similar in its reactions to an albumose, 

 is added to the blood and is excreted by the urine (Bence Jones' 

 Albumosuria). 



Although globulin may occur along with albumin in the urine, or 

 even in some cases independent of it, it is of no practical importance to 

 distinguish between them, so that the tests about to be described 

 include both bodies. 



