The teaching of engineering and a change in liberal arts curricula, both stimulated by industrial growth, encouraged the creation of specialized courses in the sciences. By the 1890s, Gingras argues, trained researchers had begun to appear in Canadian universities. The technological demands of the First World War and the founding, in 1916, of the National Research Council of Canada (NRC) accelerated the growth of scientific research. The Transactions of the Royal Society of Canada could no longer publish everything submitted to it because of the disproportionately large number of research papers from the fields of science. In response, the NRC created the Canadian Journal of Research, a journal specifically dedicated to the publication of scientific research. By 1930, a stable, national system of scientific research was in place in Canada. Following the dramatic increase in the national importance of their disciplines, scientists faced the problem of social identity. Gingras demonstrates that in the case of physics this took the form of a conflict between those who promoted a professional orientation, necessary to compete successfully with engineers in the labour market, and those, mainly in the universities, who were concerned with problems of the discipline such as publication, internal management, and awards. Physics and the Rise of Scientific Research in Canada is the first book to provide a general analysis of the origins of scientific research in Canadian universities. Gingras proposes a sociological model of the formation of scientific disciplines, distinguishing the profession from the discipline, two notions often confused by historians and sociologists of science.

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and less as the emanation unden\'ent radioactive decay, and it became motion less after about 30 seconds. Since this process was occurring very rapidly, Hahn and Sackur marked the position of the pointer on a scale with pencil marks. As a timing device they used a metronome that beat out intervals of approximately 1. 3 seconds. This simple method enabled them to determine that the half-life of the emanations of actinium and emanium were the same. Although Giesel's measurements had been more precise than Debierne's, the name of actinium was retained since Debierne had made the discovery first. Hahn now returned to his sample of barium chloride. He soon conjectured that the radium-enriched preparations must harbor another radioactive sub stance. The liquids resulting from fractional crystallization, which were sup posed to contain radium only, produced two kinds of emanation. One was the long-lived emanation of radium, the other had a short life similar to the emanation produced by thorium. Hahn tried to separate this substance by adding some iron to the solutions that should have been free of radium, but to no avail. Later the reason for his failure became apparent. The element that emitted the thorium emanation was constantly replenished by the ele ment believed to be radium. Hahn succeeded in enriching a preparation until it was more than 100,000 times as intensive in its radiation as the same quantity of thorium.

This book presents the proceedings of the IUPESM World Biomedical Engineering and Medical Physics, a tri-annual high-level policy meeting dedicated exclusively to furthering the role of biomedical engineering and medical physics in medicine. The book offers papers about emerging issues related to the development and sustainability of the role and impact of medical physicists and biomedical engineers in medicine and healthcare. It provides a unique and important forum to secure a coordinated, multileveled global response to the need, demand and importance of creating and supporting strong academic and clinical teams of biomedical engineers and medical physicists for the benefit of human health.

The Banff NATO Summer School was held August 14-25, 1989 at the Banff Cen tre, Banff, Albert, Canada. It was a combination of two venues: a summer school in the annual series of Summer School in Theoretical Physics spon sored by the Theoretical Physics Division, Canadian Association of Physi cists, and a NATO Advanced Study Institute. The Organizing Committee for the present school was composed of G. Kunstatter (University of Winnipeg), H.C. Lee (Chalk River Laboratories and University of Western Ontario), R. Kobes (University of Winnipeg), D.l. Toms (University of Newcastle Upon Tyne) and Y.S. Wu (University of Utah). Thanks to the group of lecturers (see Contents) and the timeliness of the courses given, the school, entitled PHYSICS, GEOMETRY AND TOPOLOGY, was popular from the very outset. The number of applications outstripped the 90 places of accommodation reserved at the Banff Centre soon after the school was announced. As the eventual total number of participants was increased to 170, it was still necessary to tum away many deserving applicants. In accordance with the spirit of the school, the geometrical and topologi cal properties in each of the wide ranging topics covered by the lectures were emphasized. A recurring theme in a number of the lectures is the Yang-Baxter relation which characterizes a very large class of integrable systems including: many state models, two-dimensional conformal field theory, quantum field theory and quantum gravity in 2 + I dimensions.