314 URINE. [CH. XII. 



Pipette off a little of the deposit, if any, and examine it on a slide 

 under the high power of a microscope. 



Lactosazone crystallises in characteristic clumps with project- 

 ing spines ("hedge-hog" crystals). It can be recrystallised by 

 filtering through a small paper, washing with a small amount of 

 distilled water, and then passing about 4 cc. of boiling water through 

 the paper into a clean tube. The filtrate is boiled and passed 

 through the paper two or three times, boiling between every filtra- 

 tion. On allowing the solution to stand, typical crystals of the 

 osazone separate out. 



389. Mucic acid test. TOO cc. of the urine and 20 cc. of pure 

 concentrated nitric acid are evaporated in a wide and rather shallow 

 beaker on a boiling water bath in a fume chamber. The evaporation 

 is continued until the fluid becomes clear, and brown fumes are no 

 longer evolved. The total volume is then about 20 cc. Remove 

 the beaker from the bath and transfer the contents to a smaller 

 beaker, washing out with a small amount of distilled water. Allow 

 to stand over-night in a cool place. The formation of a white 

 crystalline mass of mucic acid indicates the presence of lactose in the 

 urine. Dilute the fluid, collect the crystals on a small filter and 

 wash with cold water. Microscopically the crystals are seen to be 

 very pointed prisms with oblique angles. The melting point is 

 213 215 C. It can be weighed and titrated with standard 

 alkalies, its equivalent weight being 105. 



NOTE. Mucic acid is COOH.(CHOH) 4 COOH. 



10. The Acetone bodies. 



The acetone bodies found in urine in certain forms of 

 the condition known as " acidosis " are 

 Acetone. CH 3 .CO.CH 3 . 

 Aceto-acetic acid. CH 3 .CO.CH 2 .COOH. 

 /3-oxy-butyric acid CH 3 .CH(OH).CH 2 .COOH. 



The acetone must be regarded as a decomposition 

 product of aceto-acetic acid, which loses CO 2 on being 

 heated. The excretion of the acetone bodies depends 

 on the inability of the tissues to oxidise completely the 



