The use of the scanning electron microscope for the study of weathered wood

The use of the scanning electron microscope for the study of the changes in the structure and ultrastructure of weathered wood was evaluated in a study of wood exposed to natural weathering for several hundred years. Stereoscan photographs taken of the surface structure of wood revealed in detail the mechanism of the structural breakdown, which could not be found by using the light microscope or the conventional transmission electron microscope. The gradual and very slow deterioration and ultimate destruction of the middle lamella, the various layers of the cell wall and the cohesive strength of wood tissue as well as the wood fibres are illustrated by a serious of photographs. Since no preparative technique can be used which would interfere with the surface of the weathered wood and due to the deep three-dimensional change in the structure, the scanning electron microscope was found to be the ideal instrument for the study of the structure of weathered wood at both high and low magnification with excellent resolution of detail.