320 Aso, On tlic Naliircof Oxidases. 



10 tinies ()!' iis volunie oi' wnlcr and tested again. Hereiipon 

 very strong color reactions for oxidizing enzyms were still ob- 

 tained and a faint Griess reaction, but tlie liberation of iodine 

 was not more observed, wliat is a furtlier proof tliat the sub- 

 stance producing the guaiac reaction is not identical with that 

 wliicli produces tlio jodino reaction. 



Coiiclusioii. 



1. Tlie guaiac reaction for peroxids is not so sensitive as the 

 potassium-jodid-starch reaction. 



2. The guaiac reaction for nitrites is niuch weaker than the 

 iodine reaction for nitrites. 



3. The reason why certain plantjuices which can liberate 

 iodine loose that property on heating is very probably due to 

 the acidity of the juice and the presence of traces of amido- 

 compounds, which is a very favorable condition for the decom- 

 position of nitrites. 



4. It was positively shown that the substance which 

 gives the guaiac reaction is not the same as that which 

 liberates iodine. 



5. While the white Underground steni of the peaplant gave 

 traces of nit rite reaction, this was never obtained with the green 

 parts of these plants, nor with the root. 



