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The existence of distinct antigenic relationships between measles, rinderpest and canine distemper was confirmed and extended. The nature and extent of the serological cross-reactions were significantly influenced by the type of host and the degree of exposure to the viruses. In natural hosts, the homotypic and heterotypic antibody responses were similar. In heterologous hosts, however, exposures to the viruses resulted in antibody responses characterized by a range of cross-reactions which indicated that measles and rinderpest were more efficient antigens than canine distemper. 1. Measles virus vas related to rinderpest virus through its envelope and nucleocapsid antigens such that measles haemagglutination and haemadsorption were specifically inhibited by measles and rinderpest antibodies. Moreover, measles virus reacted with rinderpest antibodies in complement-fixation and neutralization tests. However, no reaction occurred when measles virus was diffused through agar gels against rinderpest antibodies. Measles virus was related to distemper virus through the nucleocapsid antigens such that measles antigens reacted with distemper antibodies in complement-fixation tests. In addition, a relationship through the envelope antigens was occasionally demonstrated; a few sera from distemper-convalescent dogs specifically inhibited measles haemagglutination. On the other hand, hyperimmune anti-distemper sera prepared in cattle, horses and rabbits never inhibited measles haemagglutination. Measles antibody neutralised distemper virus and reacted with distemper complement-fixing antigens but no link was evident in cross-immuno-diffusions tests. Rinderpest and distemper viruses were related through the nucleocapsid antigens such that rinderpest antibodies neutralized distemper virus and reacted with distemper complement -fixation and precipitating antigens. 2. Single exposure of animals to measles resulted in the production of antibodies reactive with measles and distemper viruses. Anamnest_ic responses ensued in sensitized animals, on challenge with heterotypic live virus only. Single inoculation of animals with rinderpest virus produced antibodies reactive with rinderpest, measles and distemper viruses. Single exposure of dogs and multiple exposures of other animals to live distemper virus stimulated the production of distemper antibodies and sometimes antibodies reactive with measles antigens. Challenge inoculation with live or inactivated heterotypic virus resulted in anamnestic response. 3. The parameters of measles haemagglutination, haemadsorption, haemagglutination -inhibition, complement- fixation and neutralization tests were studied. Measles and distemper-infected tissues were rich in complement- fixation and precipitating antigens. Production of measles and distemper antigens in cell cultures, however, was poor and was not influenced by the cell type, the age of the cells, dose of virus and temperature of incubation. The yield of measles haemacgiutinins was, however, augmented by pre - treatment of the cells with actinomycin -D and by treatment of the harvests with deoxycholate or a combintion of Tween -80 and ether. Measles virus agglutinated fresh and formolized simian erythrocytes only and the titres were enhanced by pre- treatment of the erythrocytes with neuraminidase. Heterologous agglutinins for simian erythrocytes were found in all animal sera tested. Non -specific inhibitors removable by treatment with kaolin, acetone or a heparin- manganous chloride mixture occurred in cat, dog, ferret and rat sera.

Experimental investigations to determine the nature of eddy diffusivity distribution near the wall of a turbulent stream have, until now, been based on measurements taken directly in the momentum and thermal boundary layers in enclosed flows. Owing to the difficulties inherent in taking measurements close to the wall, the uncertainties associated with these experimental determinations are of the order of - 15 per cent. The investigation reported here was intended to improve upon these results by avoiding any measurements within the boundary layers themselves. The objective was, in mathematical terms, to determine the first term or the first two terms in a polynomial representation of the eddy diffusivity distribution in "wall" turbulence. This objective included the variation of the turbulent Prandtl number near the wall. The procedure adopted was.as follows. The wall temperature distributions in the thermal entrance length of a thin pipe heated. by wall conduction from a heat source situated downstream of the test length were measured for several flow rates. The air flow through the test-section was fully established and a detailed knowledge of the flow conditions was obtainable from the recorded experimental measurements. It was assumed that the eddy viscosity distribution near the wall is known.

Self diffusion coefficients of oxygen in molten vanadium pentoxide have been measured using the capillary reservoir method with the stable isotope 0 18 as the Tracer. The non radioactive tracer necessitates incorporation in the procedure of an analytical method for the quantitative evolution of oxygen from the oxide for the mass spectrometric analyses of the isotopic contents. An apparatus has been described for each analyses, using bromine pentafluoride for quantitative fluorination of the oxide and subsequent mass analysis of the evolved oxygen. Diffusion coefficients have been measured as a function of temperature and of composition (stoichiometry) of the melt. The results are discussed in terms of the current theories of diffusion in liquid state. It is concluded that molten vanadium pentoxide does not possess 1 network 1 characteristics to any great extent in its mass transport behaviour and that anionic diffusion is unlikely to be free volume controlled but rather energy controlled. The relationship between the transport properties Viscosity and diffusion, are discussed and it is suggested that different mechanisms are operative in the two processes. Using coulometric titrations in conjunction with the solid oxide electrolyte Zr 02.yz03 and Fe0 evidence for the presence of an univariant equilibrium involving the molten pentoxide and a second condensed phase at comparatively high oxygen partial pressures have been obtained.