1: 2 GLYCOLS are oxidatively cleaved to carbonyl compounds by sodium bismuthate in an acid medium, the reagent thus behaving in a similar way to periodic acid1and lead tetra-acetate2: α-hydroxy acids are degraded to the lower aldehydes.Two principal methods of experiment have been used, (a) The reagent was added to a solution of the glycol in glacial acetic acid and stirred or shaken at, or slightly above, room temperature, until the colour was discharged and a clear solution resulted (taking a few minutes or several hours); this procedure is also suggested as a convenient test for these classes of organic compounds. (6) The reaction was similarly carried out with the glycol in aqueous (purified) dioxan solution in the presence of phosphoric acid, the initially yellow-orange suspension being ultimately replaced by pure white^bismuth phosphate. Commercially available sodium bismuthate with an oxidizing capacity (towards ferrous sulphate) equivalent to 82-84 per cent NaBiO3 was used throughout the work. The following substances have been oxidized on the 0-01-mol. scale and the products isolated as derivatives in good yield (70-100 per cent), the name of the oxidation product being given in parentheses: ethylene glycol (formaldehyde); diethyl tartrate (ethyl glyoxylate); cis- and trans- cyolohexane-1: 2-diol (adipic aldehyde); hydrobenzoin (benzaldehyde); lactic acid (acetaldehyde); man-delic acid (benzaldehyde). The initially rapid oxidation of lactic acid in aqueous solution soon stopped if the calculated amounts of reagent and lactic acid were used, presumably owing to the presence of unoxidizable esters. The reaction has been applied successfully on the 0-25-mol. scale for the preparation of ethyl glyoxylate and adipic aldehyde, and also of pelargonic aldehyde and azelaic aldehyde acid from 9: 10-dihydroxystearic acid.This type of oxidation is being further investigated, and work has been started on the oxidation of olefines by the same reagent: a full account will be published elsewhere in due course. Note added in proof. In recent experiments the use of A.R. sodium bismuthate has been found more convenient, on account of its more uniform physical state