310 THE MICROSCOPIST. 



deposit in disease of the bladder may be mistaken for 

 mucus when it is pus altered by the action of carbonate of 

 ammonia. 



Pus is formed often from the germinal matter of epi- 

 thelium, so that a small quantity in urine is not neces- 

 sarily a sign of serious disease. In large quantities pus 

 forms an opaque cream-colored deposit, which becomes 

 glairy and tenacious by the addition of liquor potassse. 

 The addition of the latter will dissolve white urates, and 

 serves to distinguish pus from them as well as from phos- 

 phates, which are little affected by it. The microscope, 

 however, is the best test. 



Purulent urine is usually acid if of renal origin (if tested 

 immediately), and is alkaline and ammoniacal in suppura- 

 tion from the bladder. Coexisting epithelium, etc., is 

 often of value in determining the origin of pus. Pus- 

 globules under the microscope, if long removed from the 

 body, are granular and show from one to four nuclei when 

 treated with acetic acid. In fresh pus-corpuscles, espe- 

 cially in warm weather, amoeboid motion is often seen. 

 In a late period of catarrh of the bladder but little epi- 

 thelium may accompany the discharge, but crystals of 

 triple phosphates occur generally in pus derived from the 

 bladder. 



The clinical significance of pus in the urine is quite 

 varied. It may follow renal inflammation, and often ap- 

 pears in albuminuria following fevers and in renal em- 

 bolism. Abscesses opening into the urinary tract, cysti- 

 tis, cancer of the bladder, suppuration of the prostate, 

 gonorrhoea, and gleet may all give rise to purulent urine. 

 Accidental mixture from lochial or leucorrhoeal discharges 

 is also possible. 



BLOOD. 



Blood may sometimes be recognized by the eye in urine 

 from its smoky or dingy tint, especially in blood from the 



