McGill University Thèses et mémoires publiés en 1948

Epilepsy has been defined as a tendency to recurring epileptic seizures, which areproduced by excessive neuronal discharge with the nervous system. It is not strictly a disease but a symptom of disease (Penfield and Erickson, 1941). Pathologically and anatomically the eiplepsies differ widely byt are joined by the common physiological mechanism manifested by the seizure. Clinically two types have been distinguished, the symptomatic in which some pathological cause such as cerebral tumar can be demostrated, and the Idiopathic (essential or cryptogenic) in which no cause can be found (Penfield and Erickson, 1941). It is this syndrome or disease entity which …  Lire la suite

Initial observations on the microwave absorption spectrum of methylene chloride have been made with a double modulation spectrometer. A total of twenty-eight lines has been found in the wave-length region round 1.25 cm. Twelve of these are contained in four closely spaced triplets. This spectrum is consistent wiiih the rotational spectrum calculated from the rigid asymmetric top model of the molecule and a tentative assignment of transitions is made. affective rotational constants and moments of inertia are obtained from the observed results. The hyperfine structure observed is thought to arise from the chlorine nuclear quadrupole moments but no attempt is …  Lire la suite

Higgins, B. (Supervisor)  Lire la suite

During the last decade, increasing interest has been shown in the isolation of large quantities of pure amino acids from proteins, for nutritional and medicinal therapy, and for other pure and applied research problems. Much progress has been made in improving methods of fractionation of protein hydrolysates, but most methods are still unsatisfactory. Fairly good methods have been devis for the isolation of basic and acidic amino acids, but the neutral amino acids are considerably more difficult to separate. [...]  Lire la suite

An experimental and theoretical examination has been made of the gamma-radiation inside and in the vicinity of extended radioactive sources. Initial ionisation experiments are described in which the "air-wall" chamber method is used to study the gamma-radiation arising from extended sources composed of radio-cobalt (Co60) in aqueous solutions* Coincidence counting measurements are described for determining the absolute radioactive content of a sample Coou source. An approximate theoretical analysis is presented for multiply-scattered gamma-rays for a point source and an extended source* Previous theoretical predictions on the relationship between the roentgen and absolute energy units have been confirmed experimentally for the …  Lire la suite

In 1905 Langevin gave the first satisfactory account of the magnetic properties of materials. His work was based on the configuration of the electron shells and sub-shells in the atom, that is, on the magnetic moment of the atom. With the exception of some additions resulting from the quantum theory of the solid state, Langevin’s work still remains the basis for the modern theory of magnetism. Now the experimental work carried out by the writer involved a study of the diffraction patterns of silver (diamagnetic) and tin (paramagnetic). The nature of these diffraction patterns depends on the crystal structure of …  Lire la suite

[...] Expressions are now available for the overall rate of polymerization and the average degree of polymerization which can be compared directly with experimental data. However, these are not sufficient to determine unambiguously the individual rate constants of the different elementary steps, having only two equations and at least three unknowns. Other expressions are required which combine these same unknowns with directly measurable quantities. One of these is the distribution function of the polymer formed after different lengths of time under various experimental conditions. Attempts have been made in this direction by Ginell and Simfca (10) and Eyring et al …  Lire la suite

During the last thirty years there has developed a trend of investigation designed to ascertain the actual material necessary for the growth of various micro-organisms. Such research was initiated because of the desire to culture bacteria in media of known chemical composition. Originally culture media were complex and designed to provide nutrients such as were found by organisms in their natural environment, but the discovery of bacteria which require special conditions for cultivation attracted attention to the possibility of nutritional deficiency even in complex mediaj therefore knowledge was lacking on the behavior of organisms whose nutrient requirements were most exacting. …  Lire la suite

A cold cathode ion source which possesses to a high degree the reciuirements for a synchrocyclotron proton source has been developed. IWo variations, one of electrode configuration and one of mode of Operation, each produce currents sufficiently high to be of value either in steady or In pnlsed Operation. The maximum consistently obtained total ion Output currents in the cyclotron field (16,000 oersteds) were: [...]  Lire la suite

The basis of much biological experimentation is to be found in human disease processes. It is probably generally true that the ultimate objective of such experimentation is the advancement of the knowledge of a human disease. This is indeed true of the work to be presented here. In order that proper orientation be preserved, a preliminary discussion will center upon those aspects of the human disease corresponding most closely to the affection produced experimentally in this work.[...]  Lire la suite

Although acetic acid has been found to be produced by brain tissue, it has also been found to be metabolically inert when added to brain slices and suspensions. That brain tissue, which carries on the synthesis of acetylcholine as a phase of its functional activity, can have no use for added acetate, was thought to be an interesting paradox. Carbohydrate is the main, if not the only, source of metabolic energy in brain tissue, and the acetate formed by brain tissue preparations is apparently derived from intermediary products of carbohydrate metabolism. [...]  Lire la suite

In spite of the early and brilliant observations of clinical pathologists, notably Rokitansky, who first called attention to the association of brain damage and pathological changes in the stomach, suggesting a neurogenic basis for ulcer formation, this concept was for many decades overshadowed by the views of Virchow and his followers who held that peptic ulcer was essentially a local disease. Although the neurogenic concept was later supported by both experimental and clinical studies, it was not until the publication of Gushing*s Balfour Lecture, relating peptic ulcer to disturbances in the interbrain, that the interest in this aspect of ulcer …  Lire la suite

The Good Hope mine at Hedley , British Columbia , was discovered four years ago . Since then , a few thousand tons of gold ore have been mined . The purpose of this paper is to present the evidence that has been assembled indicating the controls that resulted in the formation of the known orebodies . The ore occurs as irregular bodies of skarn within the limestone members of an assemblage of volcanic rocks and limestone lenses . The writer concludes that the skarn bodies were produced by alteration of limestone , that the gold was introduced during this …  Lire la suite

This study has been stimulated by the increasing interest and efforts in the preschool education movement in Montreal, in which the writer has been fortunate to have had an active part. It has been the goal of the writer to help those people teaching and directing nursery schools in this area to establish minimum standards of education. It is hoped that data from the present study may be, in some way, useful in accomplishing this goal.[...]  Lire la suite

A study of the beta decay of 275 day Ce144 and its daughter 17.5 min. Pr144 , has been made using a thin lens magnetic spectrometer. Analysis of the beta-spectrum Indicates the presence of five spectra with end-points at 3.06 ± 0.09, 1.05 ± 0.05, 0.517 ± O.O36, 0.303 ± 0.020, and 0.179 ± 0.015 Mev. The first three have been assigned to Pr1 , the remaining two to Ce1 . Conversion lines at 90.1 ± 0.9 and 125 ± 1.3 Kev. are attributed to internal conversion of a 132 Kev. gamma-ray following the 0.179 Mev. beta-disintegration of Ce144 . …  Lire la suite

The investigation to be described in this thesis forms part of a larger study which has been carried on in the Department of Biochemistry at McGill University since January 1940. The work was initiated at the beginning of the second World War under the sponsorship of the National Research Council of Canada with the object of improving the methods of preserving and administering human blood and with a view to the application of improvements in the use of blood in the treatment of the wounded. During the years of the war rapid advances were made in blood préservation as a …  Lire la suite

Throughout the eighteenth and nineteenth centuries, Hume's philosophical -writings received little attention, except in Scottish circles, and it was not until the present century that Hume came to be generally regarded as one of the greatest British philosophers. At the time when I began this thesis, there was still relatively little published criticism of his ethical thought, for reasons which are discussed elsewhere. Interest has largely been confined to his epistemology, and his ethics have been neglected or treated as subsidiary to his theory of knowledge. It was never suggested, I think, until Professor Kemp Smith's Philosophy of David Hume …  Lire la suite

Microchemlcal analysis is one of the many methods used in the chemical examination of minerals. This method requires a petrographic microscope and also a knowledge of optical mineralogy. Since the microchemlcal method requires only a small sample, it is preferable to other methods in determinative mineralogy. The purpose of this paper is to present a description of the characteristic reactions and of the optical properties of the resultant crystalline precipitates of certain common elements. The optical constants are worked out in detail, in so far as the technique used permits. It will be noted that a number of these are …  Lire la suite

While the large North American cities are a comparatively recent phenomenon, they have come to play a role in national life, hardly commensurate with their age and amount of territory they occupy. There has been a continual tendency for the city to grow both in population and area at the expense of the rural areas, small towns, and the nearby semi-rural countryside. [...]  Lire la suite

Detection of ionizing radiations by the fluorescence they cause in certain substances was first performed by Lord Rutherford. It was found that a single a particle on hitting a zinc sulphide screen produced enough light for the flash to be registered visually. This technique could not be applied to other radiations then known (β and γ rays) since these have considerably lower ionizing power and the energy released in the fluorescent screen was below the sensitivity of the eye. The principle however remained and awraited the appearance of a light detecting instrument more sensitive and reliable than the human eye. …  Lire la suite