HANDBOOK FOR BIO-CHEMIC%L fc^jTRTTAEY^ 91 



with an equal volume of water. Lastly, add a few drops of a 

 ferric sulphate solution, when a deep blue coloration will be 

 produced in the cold after some time or immediately on 

 warming. Solid proteids are also colored blue by this reac- 

 tion. 



REOCH'S Test (Albumin). See Macwilliam. 



REOCH'S Test (HCl in Contents of Stomach). A mixture 

 of citrate of iron and quinine and potassium sulpho-cyanide 

 is colored red by the gastric juice or contents of the stomach 

 containing free hydrochloric acid. 



REYNOLD'S Test (Acetone). Precipitate HgO from a mer- 

 curic chloride solution by adding an alcoholic caustic potash 

 solution. To this freshly precipitated HgO add the liquid 

 to be tested for acetone, shake, and filter. In the presence 

 of acetone the filtrate contains mercury, due to the acetone 

 dissolving freshly precipitated HgO. The mercury is de- 

 tected in the filtrate by means of ammonium sulphide, which 

 turns black. 



ROBERT'S Test (Glucose in Urine). Take the specific 

 gravity of the urine at a known temperature by means of a 

 urinometer or py kilometer supplied with a thermometer. 

 Now acidify slightly with tartaric acid and add a piece of 

 yeast the size of a pea and shake. Allow to stand at the 

 temperature of the room, or, better, at 20-25 C., for 24-48 

 hours. The fermentation by this time will be finished. Now 

 filter through a dry filter and cool to the same temperature 

 as you took the specific gravity before fermentation. Now 

 take the specific gravity again. 



Each degree of specific gravity lost represents 1 grain of 

 glucose to the ounce of urine, or if the number of degrees 

 lost in specific gravity is multiplied by the factor 0.23 we 



