The pigments, which were used in testing their inhibitive properties before, were mixed with boiled linseed oil in volume ratio of 20% pigment and 80% oil; and then were painted on the cleanly polished iron plates.
After it was dried for 10days, the film was scratched with sharp recording needle enough to reveal the iron surface clearly, and then kept it in touch with the aqueous solution of 0.001mol NaCl.
Twenty four hours afterwards, grades of the rusting at the scratched place were examined.
This scratch test (Ritz-probe) was proposed by U.R.Evans, and reported to be simple and useful method to examine the effect of anticorrosive paints.
The author repeated this test to make the relation clear between its result and the inhibitive value of the pigment itself; and it was ascertained that they are closely related to each other as follows.
Almost all the pigments, having not rusted by the scratch test, have shown the property of rust inhibition;and as an exceptional case there were some pigments,which have rusted in the scratch test in spite of their inhibitive property.
But in the case of rust stimulative pigments, all they have rusted, without exception,in the scratch test.
Among the 3 new pigments,prepared by the author on trial, two have rusted and the other one has not rusted in this test.

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The pigments, mixed with oils as described in the previous report, were painted on the polished iron plates, and after drying for 10 days, the painted plates were dipped for 24 hours in 0.5 % aqueous solution of Copper Sulphate.
When the iron plate touches with Copper Sulphate through the paint film, brownish metallic copper may precipitate on the film, therefore we can jade the grade of permeability of the film from the amount and the magnitude of copper precipitates.
Between the impermeability of the film and the result of the scratch test of the film, no special relation was found.
While almost all the pigments, which had given the impermeable film as the paint, have had rust inhibitive property by themselves.
Impermeable film was given by the following pigmets: Zinc Oxide, Litharge, Red Lead, Chrome Yellow, Zinc Yellow, Three new pigments made by the author on trial, Ultramaline, Carbon Black.
The pigments, which have shown good results in the inhibitive property by themselves, the scratch test and the impermeability of the film as the paint, were as follows : Litharge, Red Lead, White Lead, Chrome Oxide, One of the new pigments prepared by the author.

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[in Japanese]

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