As o. On tlie Nature of Oxidases. 
323 
23 grams of tlie buds of Sagittaria were crushed and ex- 
tracted witli 150 c. c. water. Tlie filtrate was divided into three 
equal parts. To one, a drop of dilnte acetic acid, to tlie other 
a drop of dilnte caustic potasli was added while the third ser- 
ved as control. Tliese Solutions were kept at 98 0 C for half an 
liour and tested with potassiumiodid-starcli as * above-mentioned 
after filtering. After a few hours, the following was observed: 
Control 
Alkaline 
Acid 
solution 
solution 
Distinct 
Distinct 
hTo reaction. 
Experiment witli 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 tlierefrom, some sulphanilic acid and sulphuric 
acid were added and again filtered. The filtrate gave a very 
faint Griess reaction upon an addition of c-naphthylamine hydro- 
chloride, but no iodine reaction 1 ). Also the color reactions for 
oxidizing enzyms were obtained very intensely with the origi¬ 
nal juice. 
In order to separate the substance which produces the 
guaiac reaction from that which yields the reaction of Grriess, 
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 Griess, but only a very feeble re¬ 
action with potassium-iodid-starcli. The guaiac reaction was 
however very strong. This filtered juice was mixed with about 
three times of its volume of alcohol (90 %) and the precipitate 
waslied with alcohol. The filtrate showed a distinct reaction 
of Griess, but no reaction for oxidizing enzyms nor a reaction 
with potassium-iodid-starch 2 ), while the solution of the precipi¬ 
tate showed very strong reactions for oxidizing enzyms, but no 
Griess reaction. 
In the next experiment, 35 buds of Sagittaria (about 33 
grams) were crushed with 50 c. c. water. To 60 c. c. of the 
pressed juice which yielded a very strong reaction with potas¬ 
sium-iodid-starch, 200 c, c. of strong alkoliol (90 °o) were added. 
The mixture was left for twenty four hours and filtered. The 
filtrate was evaporated on a waterbath and the residue was dis- 
solved in 20 c. c. water and filtered. The filtered liquid gave 
! ) Of comrse, tlie iodine reaction is not so delicate as tlie reaction of 
G-ries s. 
2) Perliaps tlie quantity of nitrite was too small. 
