_Estimation of Cellulose._--The author investigated the process of Lange and the 'celluloses' obtained from various raw materials. The products from the woods of birch and maple contained furfural-yielding constituents, represented by yields of 6-8 p.ct. furfural. Preference is given to the process by comparison with others, at the same time that it is recommended in all cases to examine the product for furfural quantitatively, converting the numbers into pentosane equivalents, and subtracting from the total 'cellulose' to give the true cellulose. 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: Yield of furfural Substance p.ct. Original beech-wood 13.8 After boiling 3 hrs. with 1.25 p.ct. H_{2}SO_{4} (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 (HNO_{3} + KClO_{3}) 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 UEBER DIE FRAGE NACH DEM URSPRUNG UNGESAeTTIGER VERBINDUNGEN IN DER PFLANZE. C. F. CROSS, E. J. BEVAN, and C. SMITH (Berl. Ber., 1895, 1940). ~ON THE SOURCE OF THE UNSATURATED COMPOUNDS OF THE PLANT.~