The author had reported, in a previous paper last year, the detection of growth-promoting points in vegetables by phenolphthaline method. Author studied the catalytic action of the trace elements, whose catalytic action is generally recognized to agree with the growth-promoting power. From the experimental results it is recognized that ferrous iron, manganese, cobalt and molybdenum show comparatively large oxidase and per-oxidase value, while coppor, nickel, zinc, and chromium show only small per-oxidase value. On this method, development of the color reaction of ferric iron and boron was not affected. On the experiments of water culture method, it is recognized that the sprout and growth-promoting power of a Japanese parsly, salada vegetable, radish and soybean are remarkably influenced in appearance, increase the weight and catalytic action by the adding of Fe, Mn, Cu and Co in optimum quantity. It has been shown experimentally in water culture method that iron and manganese are intimately concerned with oxidising and reducing reaction, which take place in plants. According to these results, it is suggested that iron is the main-catalyser manganese and copper etc are sub-catalyser.
The author described in a preliminary report, that the catalytic trace elements are a group in order atomic number 24Cr, 25Mn, 26Fe, 27Co, 28Ni, 29Cu, 30Zn and No. 42 Mo on separation from this group. Then, the author selected the trace elements of the atomic number continued upper position (No. 23V) and lower position (No. 31Ga, No. 32Ge) on the neighbouring to this group, and studied on the relation of the catalytic action. From these results obtained may be summarized as follows: (1) The author recognized that atomic number 23V, 31Ga, 32Ge show the positive reaction for the oxidase and per-oxidase action. (2) On studying the change on heating at 40°C in one hour, it was not influenced by cobalt, chromium, molybdenum, copper and germanium. but influenced considerably by vanadium, ferrous iron and nickel, and remarkably by manganese, zinc and gallium, (3) 1% water solution of each catalytic trace element was added to water solution of ferrous iron in the concentration of 1000p.p.m, on ph 2.0. The above solution showed very effective catalytic action. On account of these results, author could not see effectively difference between the increase and decrease of catalytic action by the electric potential difference. From the above experiments it can be said that it is difficult to reach a conclusion on the mechanism of the increase and decrease of catalytic power by the addition of the each catalytic trace element in water solution of ferrous iron. As a rule, the per-oxidase value showed more increase than oxidase value. The greater part of them on heating in one hour at 40°C decreased both of oxidase and per-oxidase value.