HANDBOOK FOR BIO-CHEMICAL LABORATORY. 81 



a glucose solution with the above solution diluted with water 

 a reduction of metallic mercury takes place. Ten c.c. of this 

 solution are reduced by 0.025 grm. glucose. 



ROBERT'S Test (Hcemoglobin). Shake the solution with 

 zinc powder or treat with a solution of zinc sulphate or acetate, 

 when a precipitate of zinc haemoglobin is formed. This pre- 

 cipitate when collected is colored red by alkalies. 



KOSSEL'S Test (Hypoxantliin). Treat the solution with 

 zinc and hydrochloric acid and then make alkaline with 

 caustic soda or potash. In the presence of hypoxanthin the 

 solution becomes first ruby red and then brownish red in 

 color. 



LACTIC ACID. See Uffelmann. 



LADEXDORFF'S Test (Blood). Treat the liquid with tinct- 

 ure of guaiacum and then with oil of eucalyptus, when the 

 lower layer becomes blue and the upper layer violet if blood 

 is present. 



LAXDOLT'S Test (Phenol). On treating the solution with 

 bromiue water a white crystalline precipitate of tribrom- 

 phenol (C 6 H 2 ,Br 3 ,OH) is produced. 



LANG'S Reaction (Taurin). On boiling a solution of 

 taurin with freshly precipitated mercuric oxide a white com- 

 bination occurs which appears as a precipitate. 



LEGAL'S Test (Acetone). Treat the acetone solution with a 

 few drops of a freshly prepared solution of sodium nitro- 

 prusside and then with caustic potash or soda solution. The 

 solution becomes ruby red in color, but if saturated with 

 acetic acid the color becomes carmine or purplish rod. 

 Oeatinin gives the ruby-red color, with sodium nitro-prusside 



