This paper clarifies the process through which two cyclotrons were built in England in the 1930s. They were developed by John D. Cockcroft at Cambridge University's Cavendish Laboratory and by Bernard B. Kinsey working under James Chadwick at the University of Liverpool, both in close cooperation with the Metropolitan-Vickers Electrical Company, Ltd. This firm was interested in commercial production of radioactive isotopes and, through development of the cyclotron at the Cavendish, aimed to gain expertise in cyclotron engineering. Development policy at the two institutions differed, with Cockcroft imitating American cyclotrons and Kinsey creating a cyclotron using new technology. While both projects were affected by the overall demands of military production, the two laboratories' respective development policies combined with their differing relations with M-V to create about one year's difference in the completion dates of the two cyclotrons.
We demonstrate in this paper how scientists in the 19th century did researches on nervous system; some scientists tried to make the nature of "nerve impulse" clear only to fail, while others chose to investigate how nervous system works, leaving the nature of the impulse unknown. A. Mosso and H. D. Rolleston, for example, attempted to detect heat produced in nerves with a view to elucidating the nature of the impulse. The heat, they believed, would suggest that "nerve impulse" was nothing but "a wave of chemical reaction" or "a wave of molecular vibration." On the other hand, C. S. Sherrington who introduced the term synapsis in 1897 to refer to the special connection between nerve cells-special in the sense it offers an opportunity for "nerve impulse" to change in its nature- refrained from examining the nature of the impulse. He believed that it was impossible for science at the time to elucidate the nature. He, therefore, focused his attention to reactions of muscles in an animal caused when various stimulations were applied on animal's skin in a remote area from the muscles. He did not probe into the working of the nerves running between the part where stimulation was given and the part where corresponding reaction occurred. He pursued his studies by using phenomenalistic approach. We call his approach "phenomenalistic" because his research focused only on contractions of muscles easily seen without probing into minute arrangement in a body. Gotch and Horsley, like Sherrington, did not argue about the nature of "nerve impulse." But unlike Sherrington, they made experiments with electrical changes produced in nerves or a spinal cord, based on the idea that "nerve impulse" should accompany certain electrical changes. Making use of their electrical method effectively, they obtained a series of quantitative data as to the electrical changes. The data they collected allowed them to explore distribution of nerves deep in a body and even led them to contemplate the existence of "field of conjunction" in a spinal cord. They introduced the concept to explain decrease in quantity and delay in transmission time of the electrical change, which was observed when a nerve impulse traversed a certain part of the spinal cord. This idea was considerably similar to "synapse" introduced six years later by Sherrington.
Going against chemical tradition, Becher using a cosmological-geological approach focussed his attention on mineral bodies and fixed peculiar Principles that were water and three Earths. It is not certain that his new Principles had any important historical values. But his hierarchical structure of matter that consisted of Principles, composite and decomposita, and his chemical mixture theory that mixture of bodies of lower order formed new bodies of higher order were his original ideas and not realized by other iatro-chemists of those days. These two ideas were to some extent imaginary and not clearly demonstrated. Nevertheless, it is important that he found two levels of composita and decomposita among matters that were actually handled by human's hands. Of course chemists had often made plural matter interact mutually to obtain new bodies. But until then it was generally believed that real existing bodies were produced by a mixture of imagined Principles and were reduced again into original Principles. The above mentioned assumptions of Becher managed to combine the chemical activities of handling actual bodies with the consideration of chemists about how matter changed and by doing so, prepared the basic conditions for understanding real matter phenomena without imaginary suppositions. Up to now. historians of chemistry have only Daid attention to Becher's 'terra pinguis' in relation to the phlogiston theory of Stahl. However, Becher's idea of the hierarchical structure of matter and his mixture theory may have contributed to the modernizing of chemistry. Therefore, they would contribute to the development of chemistry in the following age. We will discuss this point when the chemistry of Stahl is examined.
This paper explores who were the authors of science textbooks for secondary schools under the educational system of prewar Japan, with the objective to reexamine the historical involvement of science researchers or science educationists at higher educational institutions, with science education in secondary schools. In achieving this aim, the paper investigates the occupational and educational careers of the authors of science textbooks for secondary schools. Major findings are as follows : (1) In the mid-Meiji era, it was not uncommon for secondary school teachers themselves to write science textbooks for secondary schools. It is thus suggested their teaching activities played an important part in establishing the base of Japanese science textbooks at the secondary level. (2) At the end of Meiji era, the number of secondary school teachers who wrote science textbooks was exceeded by that of the educators at higher normal schools. (3) By the second half of Taisho era, however, the educators at higher normal schools were surpassed by science researchers at imperial universities. (4) Most authors were graduates of imperial universities or higher normal schools. While their respective numbers had been in the ratio of approximately 2 : 1, the proportion of imperial university graduates increased during the Showa era. Therefore, with respect to the science education in secondary schools, although the degree of pace varied according to the type of schools, the selection and organization of educational knowledge through the writing of textbooks had gradually depended more on the staffs of higher educational institutions, especially the science researchers at imperial universities.