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—When cotton is exposed for some time to the action of a solution of bleaching powder, in the cold, and with access of air, e.g. when a piece of white calico is moistened with the solution, squeezed out and exposed to the air, it is found to undergo gradual disintegration accompanied by a change in composition, and an elementary {11} analysis of the product shows it to contain less carbon and more oxygen than the original cellulose. The following percentage numbers indicate the composition of these oxidised derivatives of cellulose, and the progress of the oxidation:—

	12 hours’ exposure.	24 hours’ exposure.
C	43·78 43·47	43·00 42·90
H	5·85 6·13	6·28 6·18
O	50·37 50·40	50·72 50·92

Other oxidising agents produce similar results; even by exposure to air and light, cellulose is slowly converted into these oxidised derivatives.2 From their mode of formation, they have been termed oxy­cel­lu­loses, and to distinguish them from a series of more highly oxidised derivatives, produced by the action of nitric acid upon cellulose, which they nevertheless resemble in many of their characteristics, the prefix α is employed. The following are the distinguishing features of the α oxycelluloses as represented by the more extreme of the above mentioned products. It reduces Fehling’s solution at the boiling temperature, and the cuprous oxide is deposited upon the fibre in a state of intimate union, producing the effect of an orange dye. It attracts the basic colouring matters from their solutions and is dyed to a full shade, the depth of colour being proportionate to the amount of oxidation to which the cellulose has been subjected. See also p. 43. Treated with a warm solution of phenylhydrazine salts in water, it is coloured a bright lemon-yellow. Its most remarkable property is its attraction for the vanadium compounds, which is so powerful that combination may be proved to take place when this element in the form of chloride is presented to the oxycellulose in an aqueous solution containing not more than 1 in 1,000,000,000,000 parts.

2 Witz. Bull. Soc. Ind. Rouen, X. 416, and XI. 189.

The β oxycellulose resulting, as already indicated, from the action of dilute nitric acid upon cellulose, will be subsequently considered, under the head of the de­comp­o­si­tions of cellulose, to which the reaction which we have been considering may be regarded as transitional. {12}