A series of experiments on the bright nickel plating with saccharin, ethylencyanhydrin, and formaldehyde is carried out. When saccharin alone is added to the usual bath of nickel sulfate 150g/l, ammonium chroride 15g/l, and boric acid 15g/l the ammonium ions in the bath become effective to help deposit brighter film. Addition of saccharin and formaldehyde together to the Watt's bath is quite effective to get brighter film, at even relatively low temperatnre and high current densily. Ethylencyanhydrin is also a good additional reagent to the ordinary bath or Watt's bath with saccarin for bright nickel plating.

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Inorganic or organic acid mixed with hydrogen peroxide solution is found to have higher solubility to metal as well as its inorganic compounds such as scale than conventional acid solution.
The author also finds that the hydrogen peroxide solution has an ability to dissolve preferentially metal and scale, when it is used under suitable condition. So it can also be applied to the pickling of metals.
The dissolving of various kinds of scale which has heretofore been considered difficult to descale becomes easy almost without dissolving the metal.
Moreover, the metal surface treated by the acid solution containing hydrogen peroxide is so perfectly smooth that it can be polished, if necessary, as fine as mirror.
With the addition of hydrogen peroxide solution the pickling process is much improved to bring about many advantages in metal finishing.

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The thickness and hardness of the chromium film electrodeposited on even a plane surface are never uniform, but vary from place to place of the cathode plate.
Regarding this variation, the author carried out a series of experiments of chromium plating under the following conditions:
1. Bath composition: CrO₃ 250g., H₂SO₄ 2.5g., distilled water 1 liter.
2. Bath temperature: 50±1°C.
3. Size of electrode: 35mm×10mm×2mm.
4. Plating time: Changing from 1 to 2hrs.
5. Current density: Changing from 10 to 45A/dm².
6. Distance of electrodes: Changing from 1 to 5cm.
The result: The thickness and hardness of the circumferential part of the cathode plate were from 2 to 3 times as thick as, and 8.5 per cent harder than those of the central part respectively.

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This report deals with the process of lead coating over the steel surface by hot dipping. The changes of the surface conditions of the steel specimens immersed in the flux-solutions such as NH₄ Cl, ZnCl₂, SnCl₂ and SbCl₃, and the relation between the immersion time and the weight of lead coating are studied.
The results are as follows:
The weight of specimens immersed in those flux-solutions at room temperature decreases according to the time length, but, when heated at 70° to 85°C, it begins to increase after a certain length of time of heating. However, either the weight change of steel specimens or the length of treating time has nothing to do with the amount of lead coated by the subsequent process.
In the combined solution of several kinds of salts the immersion for an adequate length of time results in the nice and sufficient coating of lead.

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