Using polyvinyl alcohol as dispersing agents for silver halides in the photographic emulsion, the degree of retarding action of polyvinyl alcohol on the physical ripening of the photographic emulsion was studied.
Nine grades of polyvinyl alcohol were picked up as samples from commercial manufactures, which had different degrees of polymerization and hydrolysis.
Test emulsion with polyvinyl alcohol were prepared according to the Steigman's silver chloride emulsion formula.
As the degree of retarding action, the per cent light transmitted by test emulsions, which were diluted to 5 times by distilled water was measured.
In order to compare with polyvinyl alcohol, values of the gelatin emulsion which was Prepared under the same condition were measured.
The results were as follows;
1) In generally, polyvinyl alcohol have remarkably higher retarding action than gelatin, therefore, it shows that silver halides are highly dispersed and have been maintained in the form of fine grain in polyvinyl alcohol medium.
2) Completely hydrolyzed grades have higher values than partially hydrolyzed ones, this reason may be that OH radicals in polyvinyl alcohol molecules are absorbed by the surface of silver halides and growth of particles is inhibited.
3) Retarding action is decided in relation to three fectors, e. g., degree of polymerization, per cent of hydrolysis and concentration of solution.
4) At low degree of polymerization, the degree of change of retarding action by changing the concentration of solution is larger than that at high degree of polymerization.

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The addition agents here discussed are sensitizers or fog-inhibitors.
In order to elucidate the mechanism of action of sensitizer or fog-inhibitors on AgBr, we studied the adsorption phenomenon or chemical reactivity of the two species of typical sensitizer……thiourea and N, N-diethyl-thiourea……and the two species of typical fog inhibitors……2-amino-4-methylthiazole and 2-diethylamino-4-methylthiazole……to the surface of AgBr crystal.
The quantitative measurements of adsorbed amount were done by the tracer method with use of radioactive S³⁵ in the case of two species of thioureas, and on the other hand by the colorimetric method through the diazocoupling in the case of two species of thiazoles.
The following experiments ((I)..(4)) were executed.
(1) The adsorption experiments.
The solutions of addition agents were prepared in the various concentrations (2×10^-7 mol/cc-4×10^-6mol/cc). Each time a certain fixed amount of AgBr (9.39gr=5×10^-2mol) was added to a certain constant volume (50cc) of the solution, and then the adsorbed amount of addition agents was measured. From these results we obtained the curves of the adsorbed amounts of the addition agents vs. their initial concentrations (or residual Concentraions).
(2) The desorption experiments
The above-mentioned AgBr on which the addition agent was adsorbed was added to a certain constant volume (50cc) of distilled water and the desorption of addition agent adsorbed on the snrface of AgBr was examined. The procedure of extraction was repeated. From these results we found that in the case of thiourea only a part of adsorbed amount was extracted and the rest remaining was unextracted, and in the case of N, N-diethylthiourea its adsorbed amount was 'continuously extracted little by little by the repetition of the extraction procedure. We did not find their desorption in the case of both thiazoles.
(3) The exchange-adsorption experiments.
An attempt was made to find whether or not the addition agents once adsorbed on AgBr could be replaced by and exchanged for the sensitizing dye, when the AgBr was put into the dye solution. We observed that the thiourea and N, N-diethyl-thiourea were not at all replaced by and exchanged For sensitizing dye, but 2-amino-4-methyl-thiazole was replaced by and exchanged For it in part (about 50%), and 2-diethylamino-4-methyl-thiazole was replaced by and exchanged For it completely.
(4) The measurement of AgBr surface area.
The measurement of the surface area of AgBr was done with the sensitizing dye (2, 2- diethyl-8-methyl-thiocarbocyaninebromide)
Summarizing the above results, we concluded that both thioureas react chemically with AgBr, producing the double compound, and 2-amino-4-methyl-thiazole shows the typical monomolecular adsorption on AgBr surface, while 2-diethylamino-4-methyl-thiazole is not adsorbed so remarkably.

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A new intensity scale processing sensitometer capable of producing a top maximum exposure of 5 meter-candle-second in 1/50 second has been designed and Built. Every effort has been made to make this sensitometer easy and rapid with use in dark room. For this purpose the total enclose type was used and so, the lamp hause water cooled. The size of test film is 35/120 mm.

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A table is presented for the radiation of a brack body between 3000°k and 7000°k (100°k intervals), Values of J (λ) are given for a wavelength range of 3500Å to 8000Å at 500Å intervals, and are represented of the relative values to those of λ at 5500Å.

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10) Syntheses of mero and pentamethine cyaninedyes from Na salts of formyl compounds
11) On actions of arsenic acid on the mother components of the dyes
α-[(1-Me-2 (1H)-quinolylidene)-ethylidene]-malonic dinitrile, decomp. 290-291°C, orange crystals and Cyclohexano-α-[(1-Me-2 (1H)-quinolylidene)-ethylidene)-ethylidene]-cyanoacetate, decomp. 193°C, brown needles were obtained in yields of 73% and 14.9% from quinaldinemethiodide and ortho-formate when they were reacted using malonic dinitrile or cyclohexano cyano cyanoacetate as additional agents.
2-(3-cyano, -3-carboethoxy-allylidene)-3-et hylbenzothia zline, 4-[(3-Et-2 (3H)-benzoxazolylidene)- ethylidene]-3-Me-1-Ph-5-pyrazolone, Et α-diethyl-γ-(1-Me-1 (2H)-puinolylidene)-ethylidene)-acetoacetate, were prepared from the corresponding mother components and Na salts of formyl cyanoacetate, formyl pyrazolone compound or formyl-diethyl acetoacetate in yields of 30%, very small amount or 11.3% by heating them in the medium.
And it was found that arsenic acid reacted on the mother components of the dyes like ordinary alkalies: quinaldinemethiodide and arsenic acid gave shiny reddish beown plates decomp. 239°C (its N% was 6.552%) in a good yield, when they were treated in pyridine.

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