URINE 465 



1. Reinsch's Test. The procedure is carried out in the same manner as for 

 arsenic (see above). A piece of arsenic-free copper foil is introduced into the urine 

 acidified with one-fifth its volume of pure hydrochloric acid. The urine is, how- 

 ever, not heated to boiling, but warmed to 50 or 60 and set aside for 12 hours 

 or preferably 24 hours. Metallic mercury is deposited on the foil as a bright lus- 

 trous mirror. The foil is then washed with pure water, alcohol, ether, and dried 

 without heat, rolled into a scroll, inserted into a glass tube and heated in the same 

 manner as under arsenic. The mercury is deposited in the metallic state in the 

 form of globules readily distinguished with the microscope. 



2. Amalgamation Test. A more rapid method than the above is by amalga- 

 mation with zinc. Add 5 grams of zinc dust to the urine and heat for 15 minutes, 

 stirring continuously. Allow the amalgamated zinc to settle and decant the urine. 

 Then wash by decantation several times with pure water, then with alcohol, and 

 finally with ether and dry in air. Now introduce the dry zinc into a narrow dry 

 glass tube sealed at one end. With the Bunsen burner soften the tube about 2 

 inches above the zinc and constrict the tube by pulling the ends apart. Introduce a 

 small bit of glass wool or asbestos sufficient to support a small piece of iodine. In- 

 troduce the iodine supported by the asbestos at the constriction. Apply heat to the 

 zinc amalgam, and then gently to the region holding the iodine to gently volatilize 

 it, and immediately reapply heat to the zinc. The mercury volatilizes and meeting 

 the iodine vapor unites with it, and is deposited as the red iodide of mercury. 



CHOH 



/\ 



HOHC CHOH 



INOSITOL, 



HOHC CHOH 



'CHOH 



Inositol occasionally occurs in the urine in albuminuria, diabetes 

 mellitus, and diabetes insipidus. It is claimed also that copious water- 

 drinking causes this substance to appear in the urine. Inositol was at 

 one time considered to be a sugar but is now known to be hexahy- 

 droxybenzene, as the above formula indicates. It is an example of a 

 non-carbohydrate in whose molecule the H and O are present in the 

 proportion to form water. In other words it has the formula of the 

 hexoses, i.e., CeH^Oe. Inositol occurs widely distributed in the 

 vegetable kingdom, and because of this fact the theory has been voiced 

 that it represents one of the first stages in the conversion of a car- 

 bohydrate into the benzene ring. It is found in the liver, spleen, 

 lungs, brain, kidneys, suprarenal capsules, muscles, leucocytes, testes, 

 and urine under normal conditions. 



EXPERIMENT 



i. Detection of Inositol (Scherer). Acidify the urine with concentrated nitric 

 acid and evaporate nearly to dryness. Add a few drops of ammonium hydroxide 

 30 



