The results were confirmed by the yield of product, viz. 131 p.ct. as against the calculated 136 p.ct. They afford further evidence of the generally low limit of esterification of the cellulose molecule. From the formation of a 'normal' tetracetate--i.e. octacetate of the C_{12} unit--we conclude that 4/5 of the oxygen atoms are hydroxyl oxygen. Of the 8 OH groups five only react in the mixed esters described above, and six only in the case of the simple nitric esters. The ester reactions are probably not simple, but accompanied by secondary reactions within the cellulose molecule. * * * * * (p. 34) ~Cellulose Acetates.~--In the first edition (p. 35) we have committed ourselves to the statement that 'on boiling cotton with acetic anhydride and sodium acetate no reaction occurs.' This is erroneous. The error arises, however, from the somewhat vague statements of Schutzenberger's researches which are current in the text-books [e.g. Beilstein, 1 ed. p. 586] together with the statement that reaction only occurs at elevated temperatures (180 deg.). As a matter of fact, reaction takes place at the boiling temperature of the anhydride. We have obtained the following results with bleached cotton: Yield Calc. for Monoacetate C_{6}H_{7}O_{4}O.C_{2}H_{3}O Ester reaction 121 p.ct. 125 p.ct. {Cellulose 79.9 79.9 Saponification { {Acetic acid 29.9 29.4 This product is formed without apparent structural alteration of the fibre. It is entirely insoluble in all the ordinary solvents of the higher acetates. Moreover, it entirely resists the actions of the special solvents of cellulose--e.g. zinc chloride and cuprammonium. The compound is in other respects equally stable and inert. The hygroscopic moisture under ordinary atmospheric conditions is 3.2 p.ct. _Tetracetate._--This product is now made on the manufacturing scale: it has yet to establish its industrial value. NITRIRUNG VON KOHLENHYDRATEN. W. WILL und P. LENZE (Berl. Ber., 1898, 68). ~NITRATES OF CARBOHYDRATES.~