A study of the adsorption on metal surfaces of long chain polar compounds from hydrocarbon solution has been made and in many cases the adsorption isotherms determined. With certain metals, notably copper, lead, zinc and cadmium, the isotherms could not be determined owing t o reaction between the acid and oxide films on the metal surface. Except when reaction occurs, it is shown that the adsorption, which is reversible is not appreciably affected by the nature of the metal substrate and that it is the properties of the adsorbate molecules which primarily determine the shapes of the isotherms. I n general, ease of adsorption increases with increasing chain length and, for a given chain length, the acid is most strongly adsorbed and the ester least, with the alcohol intermediate. The influence upon adsorption of other factors such as temperature and solubility is discussed and in some cases it has been possible to calculate the free energy and heat of adsorption. When reaction between adsorbate and the metal surface occurs, i t is the physical properties of the reaction products, the metal soaps, which determine the observed behaviour.

A radiochemical analysis has been made of the EP film formed on the surfaces of the tappets of an engine lubricated with an oil containing triphenyl phosphate, labeled with phosphorus –32, as the EP additive. The results do not support the widely held view that phosphate esters owe their effectiveness as EP additives to the formation of phosphide eutectics of low melting point on metal surfaces. The results indicate the presence of metal phosphates and metal organophosphates formed from acid-phosphate intermediates derived from the ester. These findings, together with the results of subsequent rig tests, suggest that the effectiveness of neutral organic phosphates as EP additives depends on the ease with which they hydrolyze on the metal surface to form acid phosphates; the more readily the ester hydrolyzes the better its performance.

In the light of recent guidelines from the Department of Health, Catherine Hill, in collaboration with Vanessa Wright, Carolyn Sampeys, Kathy Dunnett, Sue Daniel, Lesley O'Dell and Janet Watkins, discusses the growing contribution that specialist nurses are making in promoting the health of looked after children. To illustrate this trend two projects, in Southampton and Cardiff, are examined, followed by a review of the current professional status of looked after children's nurses in England and Wales. All the evidence presented points to better outcomes and additional quality through nurse-led assessments.

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