It constitutes an important teaching material in lower secondary school that the quantity of a reaction product is affected both by the concentration and volume of the reagent solutions. On this subject, the reactions yielding barium sulfate precipitate which appeared in textbooks and/or in teacher's guides were investigated to give some essential information as follows: ⅰ) Sedimentation of barium sulfate under alkaline conditions takes much time, so that the amount of precipitate can hardly be estimated by its volume in an ordinary school hour. ⅱ) Completion of its precipitation is accelerated by the addition of strong anionic polymer floeculants (eg. OA-7), which makes the volume of precipitate proportional to its quantity for a period of 5 min. ⅲ) When barium sulfate is prepared both in acidic and alkaline solutions, the similar particle size is attained for the precipitate in the two areas by the use of cationic polymer flocculants (eg. C-360). It is also able to evaluate the amount of precipitate from its volume in the same time-course. Moreover, the necessity of polymer flocculants as a teaching material was emphasized in preparing barium sulfate precipitate, by reference to the student experiments reported earlier.

The research is based on the reference books and documents collected from the Japan side and from CIE side, and on the evidence of some science education authorities concerned in the Japanese Ministry of Education and in the local districts in those days. The fact is as follows: (1) "Teaching aims and objectives" were decided to take over the science teaching policy of the "Science-Mathematic Subject-Science (Risuuka Rika)" under the National Elementary School System (1941-1945). (2) The "Teaching Contents" of the Grades IV-VI in the "Course of Study-Science (tentative)" in 1947 came from the Unit names of the textbook "Science Book (Rika no Hon) Grades IV-VI published in 1947. (3) The "Teaching Contents" of the Grades IV-VI in the "Course of Study-Science (tentative)" in 1952 was a partial revision of the Unit names in the textbook "Science for the Elementary School Students (Shogakusei no Kagaku)," published from the Ministry of Education in 1948. (4) The "Science Ability Development Chart" in the "Course of Study-Science (tentative)" in 1947 was modified by Mr. Genjiro OKA and some science teachers with the "The Abilities Chart" in the "Course of Study for Virginia Elementary Schools" as a sample.

There were two periods in the history of Japanese science education in which supplementary textbooks variously called "RIKA-HIKKICHO (Science Notebook)," RIKA -HIKKIDAIYO (Alternative science notebook)," or "RIKA-GAKUSHUCHO" were widely used. The first period was in the late Meiji period when science textbooks were banned from use and the rika-gakushucho were used as substitute texts and the second was in the mid-Taisho period when science education was heavily promoted. This was also the time when science education was switched from primary school fifth grades to fourth grades and textbooks were in short supply. The common characteristic of these two periods is that there was a "textbook gap." This report examines these supplementary texts and attempts to thereby clarify the problems of textbook revision and to place these texts in the context, of the history of science education. Focusing on the question of why these supplementary texts came to be used, I look at the examples from Hokkaido, Yamagata, and Nagano and consider their relationship with and influence on science textbooks

By our new categorical method, we tried to analyze Sachunterricht and make clear the contents and functions of Sachunterricht and its characteristics. After making them clear, we got the main results as follows: (1) The theme of this area is the way how the child behaves, observing and familiarizing itself with its social environment, in order to think for itself how to survive in the environment. (2) The basic idea of Sachunterricht is the same as that of Heimatkunde. The contents of the field of science education are well-balanced with humankind and social life. (3) The environmental conservation and pollution are treated as the subjects of Nature. It is important for the child to study Sachunterricht, and still more important to experience what Sachunterricht includes as its theme. It is very hard for the child to observe and familiarize itself with the Nature which has tended to be spoiled recently. The child should think it important to familiarize itself with Nature. (4) Sachunterricht directs how to study animals and plants by the human's five senses. It is emphasized to make the child act with materials around itself. Sachunterricht has the child as its basis, and is not pursued within its frame. (5) Sachunterricht is one of the combined subjects which consist of biology (includes sex education), physics, chemistry, geography, art and traffic-safety education.

This paper has clarified the following two main factors. One of them is how the meaning of the physics formulae is understood by lower secondary school students who are at Piaget's formal operational stage. The other one is how the formulae are applied to problem solving without failure in the process of inquiry learning. These factors, mentioned above, are revealed to find an interrelation or correlation between the general ability of the students to solve the physics problems and their Intelligence Standard Score used to test in the light of teaching.

The electrical resistance of most metals increases linearly as the temperature rises. At the high school level, this phenomenon may be explained qualitatively using the classical electron model of conduction in metals, which contains the concepts of atom and heat. Because of the electron model, the experiment measuring the temperature coefficient of resistance, α, must be one of good teaching materials. The present paper describes a newly devised method for measuring the temperature coefficient of resistance. The advantages of the method are summarized as follows: (1) The proportional relation between resistance and temperature is directly shown without any calculation. (2) The value of α is given using a simple expression. (3) The relative error of the measured values of α to the known values is within 2-3%. (4) The time required in measurement is about 20 minutes. Hence, it is possible to finish the experiment in a class of 50 minutes. (5) The experimental apparatus, which was made on the basis of the devised method, needs only the connection of a sample of resistance and a dc voltmeter. Besides, its operation is very easy.

In this study, the historical development of the concept of mechanical energy was investigated with priority given to the vis viva (living force) controversy, and it was made clear that the questions about the learning of energy were brought from the result of investigation. In lower secondary school, the work is defined operationally only as the product of the weight and the distance of the body that was impelled upward, and the mechanical energy was established in relation with that work according to Galileo's kinematics, in a similar way to Leibniz's. Leibniz's opinion of vis viva was criticized as only a mathematical idea, so that there is a great possibility that the learning of mechanical energy in lower secondary school bring the understanding as the definition for computation. In upper secondary school, that learning is practiced by the similar method of the expansion of Newton's formulas of dynamics to d'Alembert's, Euler's and Boskovich's. They didn't pay much attention to the physical meaning of vis viva, since the students have difficulty in understanding the concept of energy, in case of the learning only by the analytic method. Then, it is necessary that the practical knowledge of s'Gravesande, and of technician Smeaton, Ewart and L. Carnot in the early years of Industrial Revolution be adopted in the science teaching. They grasped experimentally or technologically the work that meant making the various changes in the figure of the body, and therefore they paid a lot of attention to vis viva which we now call kinetic energy.

J. Piaget, who was a developmental psychologist, created many genius tasks to pose clinically upon the subjects of children during the inquiry into the developmental process of the child intelligence. Among these tasks there is one task called class-inclusion task, which means that the extension of a class concept includes all the extensions of its subordinate concepts. The authors consider that this task could be applicable to other fields of class relations of objects and concepts. In another study, one of the authors reported that the application of the task to the living things was fairy useful as a tool for the assessment of children's abilities of classification. In this study, they intended to apply the task to the chemical substances and made five problems in a questionnaire form available in the classroom. The questionnaire was given to the seventh graders to answer, who had already learned the contents in lower secondary school. Three questions out of the five are concern the macro-scopic concepts of substance; pure-substance, simple-substance and compound. Two out of the five are concern the micro-scopic concept: atom and molecule. The data thus obtained were analyzed and interpreted. The main results of this study are as follows: (1) The cognitive degree of students about the macroscopic concepts, according to the data of the former three questions, could be divided into three levels by the criterions described in the following table. Estimated numbers of each level roughly calculated became as simple as shown in the table. These numbers, by the authors' consideration, represent the actual cognitive state of the lower secondary school students about the concepts. (2) Concerning the microscopic concepts, according to the data of the latter two questions, nearly similar conclusions were obtained: 60% of level I, 30% of level II, 10% of level III. The authors consider that these numbers also represent the actual cognitive state of those students about the concepts. (3) The class-inclusion problems of the chemical substances made by the authors proved to be useful, from those facts mentioned, for the assessment of classification abilities of children. (4) These results and the children's responses for the questionnaire seem to suggest some recommendations to the teaching programs and methods in the chemistry education of the lower secondary school science.

This study is on the development of biology teaching materials to make students understand not only the relationship between nature and human life but also food problems in Science and Agriculture at the level of upper secondary school. Substances of the ruminant stomach in dairy cattle were used as initial materials of the learning. Two kinds of experiments in animal husbandry were selected carefully: 1) digestive tests in vitro with ruminant microorganisms; 2) quantitative analysis of the VFA (Volatile Fatty Acids) in the cultures. In order to adapt the actual conditions in upper secondary schools, their experiment was modified: 1) the cultures were filtrated through a polyester filter paper (No. 350; Azumi Co., Ltd.) in the digestive tests; 2) the air-dried samples were measured. In the case of the digestive test of timothy grass as the feed for dairy cattle, there were not any significant differences between the cultures with urea and without urea. In the case of rice straw, however, there were some significant differences between them. Timothy grass had a higher digestive rate than rice straw. As the results of the experiments, they were not crippled by the modified methods. We propose that all the students should learn the biological relation between agro-science and the life of organisms through the teaching materials.