The acid cleaning is considered more effective than the mechanical cleaning in order to remove oxide film from the large iron and steel equipments such as boilers and turbines. In the acid cleaning, the corrosion inhibitor is desirable to be adapted in order to reduce the attack on the metal by acid. This is especially necessary in the case of large and precious equipments.
The author investigated the acid corrosion inhibitor effect of various organic compounds to mild steel in hydrochloric acid solution and showed that Dithizone, Urotropin, Fuchsine and Methyl Red belonging to the usual organic chemical had a large corrosion inhibitor effect. As Urotropin
dissolved easily in to the acid solution among aforementioned chemicals, therefore was tractable it was concluded to use Urotropin as the inhibitor.

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Concentrated sea water and artificial brines were brought in equlibrium at 110°C, and these composition was determined. The results differed from calculated values, that was explained by deposition of langbeinite K₂Mg₂(SO₄)₃. The existance of this double salts were confirmed by X ray diffraction. Similar to 25°C, composition of the saturated with NaCl, which obtained from its analysis directly, coincided respectively: author's value and that of MAEDA (1920). On the other hand the results calculated from composition of deposited salts: that of NISHIKAWA (1933) and ONODERA (1949), was 15-50% smaller in Cl% than that of the author.

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We investigated the following particulars at “Shijoka” use the model arrangement, that is, the plane distributions of the quantity in flowing water and the number of water drops in dropping water and the size distributions of the radius in dropping water.
In the tests it was found that the utilization proportion for evaporation in space of the “Shijoka” is most valid when the sheets of bamboo branches are three.

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The reserch reported in this paper have been done on the distribution of wind velocity of flowing-down salt field and the effective space of wind came over the concentrator “Shijoka”.
In consequence of some calcurations about measured data of the wind velocity were concluded as follows.
(1) The formula of the distribution of wind velocity on flowing-down salt field are shown as
u=ay^1/n
In where u: wind velocity a, n: constant
(2) In the space from 0 to 6 meters height on the ground, the mean value of the total volume of wind are shown at 2.2-2.3 meters height.
(3) In the case of the weak wind (the wind velocity of 6 meters height in front of “Shijoka” were 2.5-2.9m/s), the wind volume revived not yet 92% at 100 meters backward, but of the strong wind (6.5-6.9m/s), reived 100% at 55 meters backward.

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There are a few reports solved by the physical metheods about the effective domain of wind backward the concentrator “Shijoka”, and especially the effective domain vary with the wind velocity and stable property of the air current on the salt field. We took into consideration these factors and obtained some solutions.

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This study was undertaken to investigate the effect of some addition agents dissolved in the super-saturated potassium chloride solution for altering the nucleation rate of potassium chloride. Following results were obtained:
1. A small amount of addition agent such as a mixture of MnCl₂ and (NaPO₃) n being dissolved in the supersaturated KCl solution, KCl grows up as a single crystal with large octahedral shape. In this case, the waiting time determined by the conductmetric. instrument-the time required for the formation of the first nucleus-is prolonged; namely the frequency of the formation of the crystal nuclei is reduced.
2. Values of activation energies, surface free energies and nucleus sizes calculated by substituting the term of the waiting time in the nucleation rate equation respectively, are increased as a result of the effect of the above agent.
From those results it is considered that the above agent behaves as if a negative catalyst in the nucleation of KCl, and so a small number of large KCl crystals deposite from the growth solution.

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The present authors had reported the result of the study on the magnesium hudrogen phosphate fertilizer (MgHPO₄·3H₂O) in this Journal, Vol.12, p.276 (1958), and then the further studies on the potassium magnesium phosphate fertilizer (KMgPO₄·6H₂O) and ammonium magnesium phosphate fertilizer (NH₄MgPO₄·6H₂O)(now in the contribution to the Journal of the Society of Chemical Industry, Japan).
In the present paper, on continuing the above described studies, the synthesis of potassium magnesium phosphate fertilizer is carried out completely by the quite different method. Especially it is very interesting if the potassium dihydrogen phosphate fertilizer (KH₂PO₄·xH₂O) will be easily obtained from the double decomposition reaction between potassium chloride and phosphoric acid solution with the byproduct hydrochloric acid and potassium dihydrogen phosphate fertilizer as shown in the following formula: KCl+H₃PO₄=HCl+KH₂PO₄
In the authors' previous report (loc. cit.), potassium magnesium phosphate fertilizer (KMgPO₄·6H₂O) was synthesized by the reaction between potassium hydroxide (KOH) solution and magnesium hydrogen phosphate (MgHPO₄) in excess phosphoric acid solution, but in the present study, this potassium magnesium phosphate was obtained by the reaction between sea water magnesium hydroxide (Mg(OH)₂) and dilute solution (1, 5, 10 and 20%) of potassium dihydrogen phosphate (KH₂PO₄) obtained above at several temperatures (15, 40, 60 and 80°C). This reaction can be writeen by the following either (1) or (2) formula:
1: Mg(OH)₂+KH₂PO₄→KMgPO₄·6H₂O
2: 3Mg(OH)₂+3KH₂PO₄→K₂Mg₃H (PO₄) ₃·9H₂O
The prepared samples of potassium phosphate fertilizers were analysed and the main compositions of MgO, K₂O and P₂O₅ and the ratio of K₂O/P₂O₅ are shown in the following table and compared with those values of two compounds (1) KMgPO₄·6H₂O and (2) K₂Mg₃H (PO₄) ₃·9H₂O. From these results, it is clear that the obtained 7 samples (a) to (g) are the mixtures of (1) KMgPO₄·6H₂O and (2) K₂Mg₃H (PO₄) ₃·9H₂O. These potassium magnesium phosphate fertilizer samples were further studied on their solubilities of main fertilizer components MgO, K₂O and P₂O₅ in citric acid solution and the hygroscopic property. The results of X-ray analysis were also the clear dissolution, that these prepared samples are to be the mixtures of the two potassium magnesium phosphate compounds (1) KMgPO₄·6H₂O and (2) K₂Mg₃H (PO₄) ₃·9H₂O.

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In the previous paper, it was found that the presence of sodium chloride and sodium dihydrogen phosphate together in the sample solution was necessary condition for the electrolytic oxidation of bromide to bromate.
In this report, the effects of amounts of two salts mentioned above and the effects of presence of magnesium and calcium ions on the quantitative oxidation of bromide to bromate were studied.
Sodium chloride was necessary to prepare hypochlorous acid and hypochlorite in the solution, and also the presence of sodium chloride itself was necessary in oxidation process. The minimum concentration was found to be 0.021mol/100ml of sodium chloride.
Sodium dihydrogen phosphate was found to be useful to obtain suitable pH value, and desirable to be more than 0.5g/100ml to maintain pH of the electrolyte in the suitable range 5.5-8.0 after electrolysis.
In the presence of calcium, it was precipitated as phosphate, so the role of pH control by phosphate was disturbed.
In the presence of magnesium, a certain stable oxidizing substance might be formed, and the complete oxidation of bromide was interferred.
By using the acetic acid-sodium acetate buffer, interference of calcium was avoided, but that of magnesium was not avoided, so magnesium should be removed from a sample before electrolysis.

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