338 



THE URINE 



It is difficult to determine the presence of blood in urine in higher dilution than 

 i to 300 with the spectroscope. The ordinary occult blood test will show it in much 

 higher dilution. 



To secure urine for bacteriological examination catheterization is rarely necessary 

 in men in the case of women it is the proper method. 



The glans penis and meatus should be thoroughly washed with soap and water, 

 after which dilute alcohol (50%) should be used. The greater part of the urine 

 first passed should be rejected and only the last portion passed should be caught in 

 a sterile receptacle. A drop of this urine may be either streaked over the surface 

 of an agar or a lactose litmus agar plate, or so treated after being first diluted in a 

 tube of sterile bouillon. 



The lactose litmus agar medium is very useful in distinguishing typhoid or para- 



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On* 



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FIG. 99. Starches and fibers found in urine. 



typhoid colonies (blue) from colon, and streptococcus or staphylococcus colonies 

 (pink). The urine may be added to tubes of melted agar and then poured. 



The most satisfactory procedure is to deposit one drop on a poured plate and five 

 drops on a second plate. The surface is smeared over with a bent glass rod first 

 smearing out the single drop and then going to the second plate without a second 

 sterilization. Neutral glycerine agar or blood agar is desirable for such organisms 

 as pneumococci or streptococci and, for the gonococcus, Thalman's medium smeared 

 over with a few drops of human serum. 



Cystitis from a colon infection gives an acid urine; that caused by Proteus 

 vulgaris an alkaline urine. 



