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The usual metods for cellulose determinations, excepting those in which the material is decomposed by total hydrolysis, are principally methods for producing cellulose preparations. In these the non-cellulosic compounds are tried to be removed as thoroughly as possible without decomposing the cellulose. However, the preparations obtained still contain different non-cellulosic components for which corrections must be made. In the method proposed by the authors a crude cellulose preparation is produced by a relatively mild treatment, and corrections are made for crude lignin and pentosans. The main feature in producing the crude cellulose preparation is shaking the samples with 3N NaOH solution in pressure bottles in a boiling water bath. The method appears to give readable results for fodder materials. For woods the results are evidently too high, especially due to mannan in the crude cellulose.

The customary Weende system for food analysis is biologically defective and even misleading. The authors have used an analysis scheme in which the conventional crude fibre determination is replaced by the determination of the total of the vegetable cell wall substances. This fraction is called membrane substances. The crude fibre is an arbitrary fragment of this total. E.g. in spruce wood the crude fibre forms about 80 % of the total of the membrane substances, and in wheat bran about 50 %. In addition the fraction »membrane substances» is divided into 4 subtractions: cellulose, pentosans, lignin, and other membrane substances. Further, a fraction called valuable carbohydrates is determined by subtracting from 100 the percentages of water, ash, crude protein, crude fat, and membane substances. This scheme has been applied to the investigation of 44 different plant products. A critical examination of the methods used has been included.