As o. On tlie Nature of Oxidases. 323 



23 grams of the buds of Sagittaria were crushecl and ex- 

 tracted witli 150 c. c. water. The filtrate was divided into three 

 equal part.s. To one, a drop of dilnte acetic acid, to the other 

 a drop of dilute caustic potash was added while the third ser- 

 ved as control. These Solutions were kept at 98 ° C for half an 

 honr and tested with potassiumiodid-starch as above-mentioned 

 after filtering. After a few hours, the following was observed: 



Control 



Alkaline ' Acid 



Solution Solution 



Distinct Distinct 



No reaction. 



Experiment with Potato. 



20 grams of potato buds (2 — 5 cm long) which had deve- 

 loped in darkness were crushed in a mortar. The pressed juice 

 was mixed with some concentrated Solution of basic lead acetate. 

 To the filtrate therefrom, some sulphanilic acid and sulphuric 

 acid were added and again filtered. The filtrate gave a very 

 faint Grriess reaction upon an addition of «-naphthylamine hydro- 

 chloride, but no iodine reaction^). Also the color reactions for 

 oxidizing enzyms were obtained very intensely with tlie origi- 

 nal juice. 



In Order to separate the substance which produces the 

 guaiac reaction from that which yields the reaction of Griess, 

 the following experiments were made: 10 buds of Sagittaria 

 (about 10 grams) were crushed with 10 c. c. water; the filtrate 

 showed a decided reaction of Grriess, but only a very feeble re- 

 action with potassium-iodid-starch. The guaiac reaction was 

 however very strong. This hltered juice was mixed with about 

 three times of its volume of alcohol (90 Vo) and the precipitate 

 washed with alcohol. The filtrate showed a distinct reaction 

 of Grriess, but no reaction for oxidizing enzyms nor a reaction 

 with potassium-iodid-starch -j, while the Solution of the precipi- 

 tate showed veiy strong reactions for oxidizing enzyms, but no 

 Griess reaction. 



In the next experiment, 35 l)uds of Sagittaria (about 33 

 gi-ams) were crushed with 50 c. c. water. To 60 c. c. of the 

 ])ressod juice which yielded a very strong reaction with potas- 

 sium-iodid-starch, 200 c. c. of strong alkohol (90 "oi were added: 

 The mixture was left for twenty four hours and filtered. The 

 filtrate was evaporated on a waterbath and the residue was dis- 

 solverl in 20 c c. water and hltercd. The filtered liquid gave 



') Of coiirse. the iodiiip reaction is not so delicate as tlxe reaction of 

 (Iriess. 



2) Perliaps the quautity of nitrite was too sinall. 



