The impregnation of timber by water-borne preservatives. I. General survey

Douglas Fir (Pseudotsuga taxifolia) timber impregnated with ‘Tanalith’ C (a copper–chrome–arsenic water-borne preservative) has been examined by optical microscopy, polarisation microscopy, X-ray diffraction analysis and electron microscopy including electron diffraction analysis. It has been established that the preservative material is situated within the cell wall. A sub-microscopic deposit of random groups of crystals (presumably basic salts) is distributed irregularly throughout the wall, while a proportion at least of the metallic components of the preservative combine with the cellulose in the cell wall to form a metal-cellulose complex.