226 BOTANICAL GAZETTE [march 



presence of peroxidases is not necessary to bring about the observed 

 reactions is shown by the following experiments: 



i. Two-tenths of a gram of dried white of egg was dissolved 

 in 10 cc. of water. To this solution 2 drops of saturated solution 

 of potassium permanganate were added. The pale brown filtrate 

 from this mixture gave intense oxidase reactions with guaiac, J 



potassium-iodide-starch, and pyrogallol. 



2. One gram of Witte's peptone was dissolved in 20 cc. of 

 water and 5 drops of saturated potassium permanganate solu- 

 tion were added. With the pale brown filtrate the 3 oxidase 

 reactions just mentioned were carried out. All were strongly 



positive. 



3. To about half a gram of tyrosin mixed with water 2 drops 



of a 5 per cent solution of potassium permanganate were added. 

 The brownish mixture gave a clear brown filtrate which oxidized 

 potassium iodide, guaiac, and pyrogallol. 



4. One-half gram of tyrosin was dissolved in hot water. To 

 the boiling solution 3 drops of a 5 per cent solution of potassium 

 permanganate were added. The pale brown filtrate from the 

 mixture gave the 3 oxidase reactions. This filtrate was boiled 

 and allowed to stand overnight, but no further precipitate was 

 formed. The filtrate still gave all the oxidase reactions. 



5. To a solution of 1 gram of glucose, 2 drops of a saturated 

 potassium permanganate solution were added. The mixture was 

 warmed until the purple color had given way to light brown. 

 The filtrate gave the oxidase reactions distinctly. Fructose treated 

 in the same way gave strong reactions with guaiac and with 

 notassium-iodide-starch, but none with pyrogallol. 



6. To a boiling solution containing 3 drops of a 5 per cent 

 potassium permanganate solution in 10 cc. of water, glycerine was 

 added drop by drop until the purple was replaced by brown. The 

 filtrate from the brown precipitate was pale straw-colored. It 

 gave all the oxidase reactions. 



7. One cc. of salicylic aldehyde reduced quickly in the cold 

 2 drops of a 5 per cent solution of potassium permanganate, form- 

 ing a brown precipitate. The pale straw-colored filtrate gave 

 reactions with potassium-iodide-starch and with guaiac. 





