HANDBOOK FOR BIO-CHEMICAL LABORATORY. 8< 



NENCKI'S Test (Indol). Inclol gives a pronounced red col- 

 oration with nitric acid containing nitrous acid. In concen- 

 trated solution a red precipitate may form. This reaction is 

 not given by skatol. 



NITROUS ACID or Nitrites. See Griess. 



NYLANDER'S Test (Glucose). Dissolve 4 grms. Rochelle 

 salts in a solution of 10.33 grms. NaHO in 100 c.c. water. 

 Add to this 2 grins, bismuth subnitrate and digest on the 

 water-bath until as much of the bismuth salt is dissolved 

 as possible. On heating 10 vols. of a glucose solution with 1 

 vol. of the above solution for 2-5 minutes a black precipitate 

 or a dark coloration is the result. 



OBERMEYER'S Test (Indican in Urine). Precipitate the 

 urine with a lead acetate solution (1 to 5), being careful not to 

 add an excess of lead solution. Filter through a dry folded 

 filter and shake the filtrate with an equal volume of fuming 

 hydrochloric acid which contains 1-2 parts ferric chloride 

 solution to 500 parts of the acid. Continue shaking for 1 or 

 2 minutes, and then add some chloroform, which takes up 

 the indigo blue produced and is colored blue. 



OBERMULLER'S Test (Cholesteriii). Fuse the cholesterin with 

 2 or 3 drops propionic acid anhydride in a test-tube over a 

 small naked flame. On cooling the fused mass is first violet, 

 then blue, green, orange, carmine, and lastly copper red. 



OLIVER'S Test (Albumin). Mix equal parts of sodium 

 tungstate solution (1 to 4) and a saturated solution of citric 

 acid, (10 to 6). The urine is floated on this solution, and in 

 the presence of albumin a white ring is obtained at the con- 

 tact of the two liquids. 



PACINI'S Liquid (Blood). One part corrosive sublimate, 2 

 parts sodium chloride, 13 parts glycerin, 113 parts distilled 



