Читать книгу A Text-book of Paper-making - C. F. Cross - Страница 49

If the student require more precise knowledge of the nature of a fibrous material than that afforded by a determination of the cellulose, the following method of analysis will prove of service.

About two grms. are taken and dried at 110–115° C. until the weight remains constant: the loss represents water. The fibre is then treated with a hot mixture of benzene and alcohol, dried as before and weighed: the loss is fat, wax, {45} &c. The residue from this treatment is then repeatedly exhausted with boiling water and again dried at 110–115° C. and weighed: the loss is put down as aqueous extract. The exhausted fibre is then treated for cellulose by either of the methods given on p. 19. The ash is determined in a separate portion.