A method of fractionating raw fleece samples and some errors encountered in its use in experimental studies of fleece growth.

Abstract

A routine quantitative method of separating raw fleece samples into five fractions is described. Moisture content at a known temperature and relative humidity is determined as the loss of weight on drying a t 105°C, wax is Soxhlet-extracted with carbon tetrachloride, suint is extracted by subsequent washings with cold distilled water, dirt is removed by washing and handpicking, and clean wool fibre remains after these fractions have been removed. Some errors detected in the extensive use of this method to provide simple criteria in a variety of field and laboratory studies of fleece growth have been examined. Recovery of original sample weight after fractionation was satisfactory and there was good agreement between the results for duplicate samples. There was a tendency for incomplete separation of suint and for ethyl-alcohol-soluble material, of the order of 1 per cent. by weight, to remain on the clean wool fibre.