The comparative evaluation of antiseptics involves many difficulties. Numerous procedures have been devised in the hope of avoiding at least some of the sources of error that arise from transfer to clinical usage of results obtained in test tube experiments. Adequate standard methods have not yet been developed; consequently studies in this field by different workers are rarely comparable. This has led to great confusion and much controversy.
Elsewhere in this issue is an article by Justina H. Hill1 of the Brady Urological Institute (whence mercurochrome originated) concerning the action of mercurochrome in comparison with some other preparations on normal human skin and in infected wounds in animals. Miss Hill presents an extensive series of experiments on the comparative bactericidal and bacteriostatic effects of 2 per cent aqueous and 2 per cent acetone-alcohol-aqueous solutions of mercurochrome and of tincture of iodine applied to normal human skin. She concludes from