45 PHYSIOLOGICAL CHEMISTRY 



then held in the bunsen flame at an angle of 20 to 25 degrees applying heat where 

 the copper foil is situated. The arsenic volatilizes and is oxidized, and deposits as 

 octahedral crystals of arsenic trioxide on the cooler part of the tube. The crystals 

 can readily be recognized by the microscope and sometimes with a simple magnify- 

 ing lens. 



MERCURY 



The rapidity of absorption of mercury depends upon a number of 

 conditions such as, mode of administration, the nature of the com- 

 pound and its physical state, the state and condition of the stomach 

 and intestines, the quantity and quality of the food in the stomach 

 and the state of the circulation of the portal of entrance. There is 

 no definite knowledge as to the form in which it is absorbed. Elimina- 

 tion depends upon the state of the excretory organs. It is eliminated 

 as an albuminate in all the excretions of the body, urine, feces, saliva, 

 sweat, tears, and milk. Elimination begins about two hours after 

 introduction. Depending upon the amount introduced and absorbed, 

 the time required for its complete elimination varies from 24 hours to 

 many weeks. Mercury may be detected in the urine by the following 

 methods. 



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 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. Intro- 

 duce 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 



