These days, arc lamps are scarcely used for the purpose of illumination, but in the history of electric technology, they have great significance. As a clue of this report, an arclamp was made by a simple method in which the lead of a propelling pencil was electrically charged with an autotransformer. Many teachers who visited us were interested in the arc lamp as a teaching material, and more detailed information was requested by them_. Accordingly, a basic study was done on the effective procedure and application method of the arclamp as a teaching material. Since the result was good enough for our purpose and the effect of its exhibition was expected, the significance and characteristics of this experiment in the education of science in lower secondary school were considered. The arclamp reported here had the following properties: 1) When the lead of a propelling pencil with a diameter of O.5mmand a length of 6cm was used as electrodes and charged with an alternating current of 90 to 130V, an electric current of 0.3 to 1. 1A ran between. the electrodes and the 1ight with an intensity of 30 to 110cd continued for 60 to 90 seconds. 2) The light intensity and the current volume were in nearly direct proportion, and the voltage between the electrodes was,, nearly constant in 50 to 60V.

Macroscopic times, like a million years or a billion years, are used in the teaching of evolution, but they were not studied satisfactorily, so, they were investigated in this study. Upper secondary school students were selected as subjects. Test items were selected from the history of evolution. The students were asked about how past items had taken place. The results showed that the students understood the sequence of items well. They indicated that the students could differentiate roughly Paleozonic Era, Mesozonic Era, Cenozonic Era and Recorded Era. But the students had two misunderstandings. (1) They underestimated the time length of evolution. (2) They overestimated the time length of Paleozonic Era, Mesozonic Era, Cenozonic Era and Recorded Era.

In this paper, the author attempts to clarify the meanings of accent shift from "exemplary principle" to "genetic principle" in Wagenschein's didactics of science (physics in particular) from the viewpoints of teaching theory, social theory, and building theory (Bildungstheorie). From the first viewpoint the accent shift in his didactics means that he aims at securing children's "true understanding" of science by keeping them from understanding of science separated from real, true, and primitive nature in science education and by securing the "continuity" from their naive understanding of nature to their scientific understanding of nature, thereby, at the same time, at their acquisition of knowledges of science as knowledges leading to building (Bildung), namely to the completion of their humanity, and at greater emphasis of these securing in genetic principle than in exemplary principle. From the second viewpoint the accent shift means that he aims at securing children's "true understanding" of science so as to prevent a split between scientists and nonscientists in society, and to form "intelligence to know about science" as a precondition for social peace. From the third viewpoint the accent shift means that he aims at emphasizing the process of "development" (Werden) of aspect of physics so as to form the perception of "aspect-character" of physics as an indispensable condition for building effect through physics teaching, and moreover, at corresponding to the change of concept of "development" which moves from the development of aspect of physics in intellectual history of human beings to that in continuous process from children's naive understanding of nature to their scientific understanding of nature.

Previously we pointed out that the distillation of cooking wine would be valuable to the students of lower secondary school in their learning about how to separate substance.. In order to confirm this suggestion, the distillation of cooking wine was conducted in two classes in ordinary school hours, parallel to that of mirin (sweet sake) cited in a textbook. An apparatus consisting of a test tube and an alcohol lamp was used in one class, and that composed of a distillation flask (a flask with a side arm) and a gas burner in another, both of which were adopted from textbooks. After this experiment, the ethanol concentration of the distillate was estimated by using gas chromatography, and the effect of the trial on the students was examined by questionnaire. This investigation gave some essential information as follows. i) Distillation of the brewing products, with either of the equipments, gives high enough ethanol concentration of the distillate (more than 50% in the mean value), so that the ethanol can easily be detected by its flame and heat of evaporation. ii) Formation of colorless distillate from red cooking wine during the distillation process seems so attractive to the students that the interest might act as a driving force to this experiment. On the basis of these facts, we concluded that the use of cooking wine is suitably fitted for a teaching material in lower secondary school, when vivid color change is used for the judgement of separation, accompanied with the detection of ethanol in the distillate by utilizing several characteristics of the compound.

In order to clarify the relationship of common plants and animals to students of elementary and middle schools the following three points were investigated using color-printed questionnaires: 1.the degree of students' direct experiences with plants and animals. 2.students'ability to properly identify the names of common plants and animals. 3.students'ability to understand the names of plants and animals in relation to their living environment. We surveyed 5324 students from the first to the ninth grades in Kobe and compared the results in terms of agricultural versus urban districts, sex differences, and grade differences. We obtained the following results: 1) More boys had direct experiences with common animals than girls did. In terms of where students live, while there is a tendency for the boys in the second and third grades in agricultural districts to have greater direct experiences than the boys in urban districts, those students in the fourth or higher grades revealed no differences whether they lived in agricultural districts or urban districts. Even in the case of girls, we observed a tendency for the first to the third graders in agricultural district to have more direct experiences than those girls in urban districts. But as far as the fourth or higher graders were concerned, the differences become smaller. 2) As for direct experiences with common plants, a large difference was noted between students' living environments. Boys and girls living in agricultural districts had many more direct experiences than those living in urban districts. Girls were shown to have more direct experiences than boys. 3) Boys were-shown to understand animals better than girls, there were., 1Lttle or no differences in the understanding of animals among boys and girls in relation to environment differences.

"The Electromagnet" is a first unit for the elementary school children to study about the interaction between electricity and magnetism. In the present study, it is described to investigate the effects of heat-treatment on the use of an iron nail as a magnetic core for teaching as electromagnet material in the unit. In order to observe the fine structure of an iron nail, a metallurgical microscope should be used. A heat-treated nail is embedded in the polyester resin, ground with sandpaper and polished with alumina to have a mirror face. The mirror face is etched with 3% nitric acid in methyl alcohol (Nital solution) and observed with a metallurgical microscope. As the results, it was proved that residual magnetic flux density (Br) of the iron nail was caused by internal strain and quenching structure (martensite). The internal strain can be eliminated with heat-treatment over the recrystallization temperature. The quenching st'lfucture can not be made at the temperature under the A1 magnetic transformation point.