will become more or less blue by the indigo formed, in pro- 

 portion to the indican originally present. According to 

 the depth of the blue color it may be designated as little, 

 much or copious. 



Oxalic Acid. This is usually found in combination with 

 lime in the form of calcium oxalate. The crystals are of small 

 size and appear in the form of dumb bells and octahedra. They 

 occur normally in greater amount in herbivorous than in omni- 

 vorous urine. They greatly increase after eating such vegetables 

 as tomatoes, fresh beans, beet-root, asparagus, apples grapes, 

 honey, and after the use of rhubarb, senna, squills, etc. Another 

 source of oxalic acid in the body is incomplete oxidation of carbo- 

 hydrates and proteids or retarded metabolism. It is therefore a 

 result of mal-assimilation and is found in dyspepsia, diabetes mel- 

 litus, etc. The long continued excretion of an excess of oxalate of 

 lime frequently irritates the kidneys, producing albuminuria and 

 grave nervolis disturbances and may lead to the formation of 

 calculi. (Fig. 18.) ' •■ 



Acetone. Normal lirine may contain traces of acetone but 

 it occurs in excessive quantities as a pathological condition.** It 

 is found in many of the fevers, certain forms of cancer, in 

 starvation, and in diabetes, when it indicates an advanced form 

 of the disease. It is associated ^ith an increased proteid meta- 

 bolism and is looked upon as a product of proteid decomposition 

 with deficient oxidation. 



Lieben-Kalfe Test. Dissolve 1.3 grams (20 grains) 

 of potassium iodide in 4 cc. (1 dram of liquor potassae. 

 Boil in test tube, after which gently pour the urine on 

 its surface. A yellow precipitate between the two solu- 

 tions indicates an affirmative tejit. A more satisfactory 

 , test is to add to the' urine a. few crystals of. iodine and of 

 iodide of potassiuin with some caustic potash. Heat. Yel- 

 '^ ■ low precipitate — iodoform, with its cha^'acteristic odor. 



Legal's Test for Acetone. Add to 5 cc. of. the urine 

 some fresh aqueous solution of sodium nitrbp'russi'de fol- 

 lowed by a little ammonia, or sodium hydrate solution'' 

 which give's a red color disappearing on boiling... Add.suf- 



* If pathological ui'ine is not available, a .small amount of acetone 

 may be added to the urine for laboratory tests. . ' 



