This pamphlet details treatments carried out by conservators of the National Gallery of Canada and scientific research in the areas of deterioration and environmental control. Carot's Le Pont de Narni revealed yellow varnish, cracks, tear repair and a glue lining. Varnish removal was with shellsol, acetone and cellosolve (2:1:1). Further examination with binocular microscope, ultra violet fluorescence and infrared photography established the extent of old restoration. Treatment procedure is detailed. A polychrome sculpture, The Virgin and Child , attributed to the Labrosse atelier, was heavily overpainted and split. Cross-section analysis determined original paint layers and gold leaf. Overpaint removal was both solvent and mechanical. The Toilet of Venus , by Boucher, part of a travelling exhibit, was examined due to flaking paint. Extensive testing revealed overpaint and retouches. The painting was cleaned, lined, and remounted on an enlarged stretcher. A detailed treatment report is included. Scientific investigations carried out by the laboratory included identification of mould from paintings returning from the tropics, examination of a recently discovered wooden head by cross-section, and continuation of studies on solvent action on paint films. This is a reference for treatments and materials used by conservators at the National Gallery of Canada in the early 1960's.