Preparation of Very Small Representative Samples of Raw Cotton

Since immature cotton fibers are colored green and mature fibers red in differential dyeing, this technique has been employed to show visually how well the fibers are mixed in the sampling of cotton. It has been shown by such dyeing that raw cotton usually con tains groups of immature fibers that tend to remain in groups that are not completely broken up and distributed, even in very small test specimens prepared for cross sectioning. The danger has also been shown of too much confidence in the mixing of fibers by me chanical blending, and of excessive loss of immature fibers, as at the combing stage of sampling. The representativeness of subsamples and of small test specimens was im proved, using differential dyeing of portions of subsamples at intermediate steps in sampling and of parts of final specimens as a guide. An extension of this type of study could well resutt in the improvement of standard procedures for the sampling of raw cotton.