A s o, On the Nature of Oxidases. 
a strong Grriess reaetion as well as the iodine reaction very cle- 
cidedly, but not the guaiac reaction while the aqueous solution 
of the well-washed precipitate gave in the contrary not the 
Gf ries s reaction nor the iodine reaction, bnt a strong guaiac re¬ 
action. Tliis result proved positively that the substance 
which gives the guaiac reaction is not the same that 
liberates iodine from potassium-iodid. 
Bach and Chodat 1 ) have mentioned that when a freshly 
cut surface of Sagittaria bulb wdth paper moistened with po- 
taslium-iodid-starch, is touched a bluish violet ring will appear 
along the peripheral tissue after a short time, further a blue 
ring with a paper moistened with guaiac tincture, and further 
with m-phenylendiamine, along the same lines. I have repeated 
these experiments and made a similar observation. Hence I took 
off the peripheral part of twenty one bulbs and crushed it with 
30 c. c. water. The pressed juice gave a strong guaiac reaction 
and a moderate Grriess reaction, but the iodine reaction only 
slightly. To 30 c. c. of the juice about 100 c. c. absolute alco- 
hol were added and the alcoholic tiltrate was evaporated to 
dryness. The residue was dissolved iu 10 c. c. water and tested 
with the following result: 
Gluaiac reaction 
Grriess’ reaction 
Jodine reaction 
bTo reaction at all 
moderately 
slightly. 
In the case of a feeble iodine reaction, the addition of a drop of 
dilute snlphuric acid is preferable to accelerate the reaction. 
The aqueous solution of the precipitate produced a very 
strong guaiac reaction, but no Grriess nor iodine reaction. Mo¬ 
reover, I carried out several tests with the juice of skinned 
bulbs according to Bach and Cliodats method, but neither 
Grriess nor iodine reaction was obtained while the guaiac reaction 
appeared very strong. Also, on application of guaiac tincture 
on the scratched surface of the freshly cut bulbs the blue color 
appeared at once, while there was no reaction obtained with 
potassium-iodid-starch. Tliis result convinced me that the bulb 
of Sagittaria (excluding tlie skin) contain common oxidase, but 
no nitrite. 
40 grams of Potato buds (2—5 cm long) were crushed and 
the juice was pressed out. Tliis juice did neither yield the po- 
tassium-iodid-starcli reaction nor the Grriess reaction. wliicli ho- 
wever appeared very weak after purihcation. About 5 c, c. of 
the juice was mixed with some concentrated solution of basic 
lead acetate and tiltered. The tiltrate was mixed with snlphuric 
acid and sulphanilic acid, then with u-naphthylaniine liydro- 
0 Berichte der D. Chem. Ges. XXXVII. 1901. Heft 1. p. 39. 
