Application of Microchemical Tests in Assessing the Quality of Ash Timber

Abstract

DURING the last few years, attention has been given in this laboratory to the study of the anatomical structure of ash timber in relation to the maximum crushing strength in compression parallel to grain. Consignments of trees from seven localities have been studied, and each site had a distinctive strength specific gravity regression. Variations in the amount of wood substance per unit volume, therefore, do not account completely for variations in strength, and it has been shown that the arrangement of the wood substance in the annual ring also influences the mechanical properties¹. The fact, however, that specimens of equal specific gravity and closely similar anatomical structure sometimes differ by more than 30 per cent in maximum crushing strength suggests that still other factors are involved and that probably the physical and/or chemical nature of the wood substance is of great importance in determining strength.