On the Nature of Oxidases. 
By 
K. Asö, Tokyo. 
In a formen article x ) I liacl sliown tliat the liberation of 
iodine from potassium iodicl by certain plantjnices does not go 
parallel witb tbe blue guaiac reaction, as Bacli liad supposed 
and tliat in one case at least, it was positively sliown tliat 
tbe liberation of iodine was dne to traces of nitrous acid. 
Tliat article bad induced Cliodat and Bacli 1 2 ) to some re- 
marks wbicb led me to make some furtlier trials. Tliese sliow 
tliat tbe view of Cliodat and Bacli cannot be generally sus- 
tained. 
In tlie first place I must adbem to my view tliat tliere is 
no paralleiism between tbe iodine liberation and tbe guaiac re¬ 
action. 3 ) In tbe second place I am convinced contrary to tlie 
opinion of Cliodat and Bacli, tliat tlie guaiac reaction upon 
peroxides is not so sensitive as tlie liberation of iodine by 
peroxids. 
In Order to prove tbis latter assertion tlie following Obser¬ 
vation was made. Tbe common para-aldeliyde of commerce lias 
generally an acid reaction and yields witb potassiumiodid-stareb 
very soon an intense blue reaction due to tbe liberation of iodine. 
I entertained tlie supposition tliat tliis reaction is not caused by 
tbe pure para-aldeliyde, but by an admixture of an organic per- 
oxid, very probably by tbe acetylbydroperoxid. 4 ) Similar per¬ 
oxids liave been observed as 'a result of autoxidation of otber 
aldebydes and also tbe common etlier forms alter long contact 
witb tbe air, an organic peroxid, wbicb sometimes even caused 
explosions in distilling sueb an old etlier to tbe last drop. 
I sbook tlierefore about 20 c. c. of commercial para-alde- 
liyde, witb an equal volume of 10 % sodium carbonate solution 
1 ) Beihefte. Bot. Centr.-Blt. XI. Heft 1. „Which compound in certain 
plantjnices can liberate iodine from potassium iodid?“ 
2 ) Berichte d. d. ehern. Bes. 1994. Heft 1. 
3 ) This view is also entertained by Bandnitz. (Monatschrift für 
Kinderheilkunde. II. Heft 8.) 
4 ) Page, B. H. (Amer. Pat.) mentioned in the Chemiker-Ztg. Benzal¬ 
dehyde (commercial) produced also the iodine reaction in traces. 
Beihefte Bot. Centralbl. Bd. XVIII. Abt. I. Heft 3. 22 
