ZUR KENNTNISS DER MUTTERSUBSTANZEN DES HOLZGUMMI.
E. Winterstein (Ztschr. Physiol. Chem., 1892, 381).
ON THE MOTHER SUBSTANCES OF WOOD-GUM.
(p. 188) According to the text-books beech-wood may be regarded as the typical raw material for the preparation of the laboratory product known as wood-gum. The author has subjected beech-wood and beech-wood cellulose (Schulze process) to a range of hydrolytic treatments, acid and alkaline, in order to determine the conditions of selective action upon the mother substance of the wood-gum. In the main it appears that this group of furfuroids is equally resistant with the cellulose constituents of the wood; in fact, that the mother substance of wood-gum is a modified cellulose, and exists in the wood in chemical combination with the 'incrusting substances.'
Of the author's experimental results the following may be cited as typical:
| Substance | Yield of furfural p.ct. |
| Original beech-wood | 13.8 |
| After boiling 3 hrs. with 1.25 p.ct. H2SO4 (residue) | 10.1 |
| " " " " 5.0 " " " | 5.6 |
| Cellulose | —isolated by Schulze process (yield 53 p.ct.) | 6.9 |
| " | after further 14 days' digestion with the Schulze acid (HNO3 + KClO3) | 5.9 |
| " | after extraction with 5 p.ct. NaOH in cold (residue) | 5.0 |
| " | after second extraction with 5 p.ct. NaOH in cold (residue) | 4.4 |