Authors have compared and discussed in details on the characteristics of the several home-and foreign-made color temperature meters being used in Japan, and results were obtained as follows.
1) Measurement of the variation of color temperature, in the open air with each meter, show that the indicated values vary with similar tendency, but the difference among them due to their individual characteristics can not be neglected.
2) The scale approximately based on the D. G. filters may be refferenced for the calibration of each color temperature meter.
3) For any other conversion filters with the different spectral transmission than the D. G. filter, the individual indications deviate considerably, so it is recommended that the spectral sensitivity of the color temperature meter elements must be made to have spectral sensibility which is approximately similar to that of the emulsion of color film.
4) It must be noticed that in some meters direction of incident light onto the photo-sensitive surface affect to make appreciable change in the indication of color temperature meter.

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The production of a latent image in photographic emulsion by friction or folding, and the desensitization of the emulsion to subsequent illumination have been investigated. For the external or shallow internal image, we observed the desensitization, but for the deep internal, sensitization.
The individual grain of silver halide deformed by pressure, was observed under a microscope. The grains strongly deformed by pressure, were blackend by development, but to subsequent illumination, were not blackend. The developable image was formed at the surface of the grain deformed by pressure, though it was not obvious how it was formed.
It is suggested that the desensitizing effect by pressure may be considered in terms of the Mitchell's theory of the latent image formation; the deformed grainhas intense structural imperfection in its interior which are favorable to internal latentimage formation. When the. deformed grain is illuminated, electrons are trapped at internal sensitivity center and then form internal latent image. On the other hand positive holes migrate to the surface of the grain and are trapped by sensitivity speck or silver nucleus which is formed by pressure. Thus surfacelatent image is dissipated, and the internal latent image is formed.

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For the ultraviolet absorbing filters which are abailable now-adays, such absorbent as tartrazine, ultrazine, R-acid, G-acid and aesculin are used, but they have the defects that they transmit-near ultraviolet light, absorb blue light, or are fluorescent or unstable to light.
We intended to make ultraviolet absorbing filters which are colorless, non-fluoresent, clear, stable to light and sharp cut. The light transmittance of flavene, flavanone, chalcone and coumarin groups were measured at the concentration of absorbents 3g/m² in alcohol or benzene.
There are interesting relations between absorption curves and chemical constitutions.
The absorption edges of flavones shift according to the number of OH and other radicals. They shift to longer wave length with the increase of OH groups and to shorter wave length with the decrease.
Flavone and coumarin group have sharp absorption curves but chalcone and flavanone group have rather flat curves.
Flavon group is the most excellent absorbent as the ultraviolet absorbing filters, because, besides being sharp cut of the ultraviolet light, it is non-fluorescent and light-fast. With these ultraviolet absorbing agents several kinds of filters were made.

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In the previous reports, author devised the separation exposure on the multilayer film in order to obtain the good color rendering effect. In this report were done the fundamental experiments as to the different conditions. At first from the transparency of three color filters, author determined the exposure ratio. Using the color positive, the condition of development temperature and time were obtained.
To do the exact sensitometry of color film, the author made three color transparent wedges and paper wedges. Thus the color fog of negatives being obtained, the exposure ratio which is given through this negative is calculated theoretically.

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