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The formation of borate complexes contributes significantly to the distribution coefficients obtained in the separation of polyhydroxy acids in borate medium. A study of a large number of straight-chain hydroxy acids shows that these contributions tend to increase with the number of vicinal hydroxyl groups and with their distance from the carboxylate group. Vicinal hydroxyl groups in gauche conformation have the ability to form strong complexes, provided that the steric conditions are favourable in other respects. The contributions of vicinal hydroxyl groups in anti conformation are much less.

Aromatic compounds containing hydroxyl and carboxyl groups are retained in aqueous medium by cross-linked polyvinylpyrrolidone due to hydrogen bonding, with the resin serving as a proton acceptor. Efficient separations were obtained in 0.001 M hydrochloric acid. With substances containing seveal proton-donating groups, improved results were obtained by using a more efficient eluent, e.g., 5 M acetic acid.

Normal thymic lymphoid cell suspensions were studied in the electron microscope. The suspensions contained cells (6–23 per cent) in various degrees of lytic degeneration with swelling and disintegration of both nucleus and cytoplasm. Only a minority of the degenerating cells showed pyknotic changes and these cells had always a well preserved cytoplasm. The percentage of degenerating cells was compared with the percentage of cells stained in the nigrosin-dye exclusion test. A close relationship between these two values was found, suggesting that supravital staining primarily affects cells in lytic cell degeneration. It appears that vital stains only affect already degenerating cells with a subsequent increase of a preexisting intracellular edema. This suggestion was corroborated by the finding that addition of nigrosin dye to thymic cell suspensions does not depress aerobic metabolism.