THE discoyJp of the insecticidal properties of D.D.T. (the Jra, para-isomer of dichlorodiphenyl-trichlor teiftan Byclosely followed by the isolation of the y-isoianlep of benzene-hexachloride, which is even more toada for some insects, has provided a great stimulus to tijesearch for new and still more potent substances especially for substances in which it may be possible to secure proprietary rights. The two insecticides above are both highly chlorinated ring compounds, and it is in this group of materials that the search seems to be most actively prosecuted at the present time. The latest product is a chemical of unrevealed composition with the empirical formula C10H6C]8. It has been produced by the Velsicol Corporation in Chicago under the name of “Velsicol 1068”, and is to be marketed in Great Britain by the Hygienic Chemical Co., Ltd. It is a viscous, colourless, odourless liquid, less volatile than benzene hexachloride (‘Gammexane’), more volatile than D.D.T. In solubility it resembles these substances, and in toxicity to insects it comes somewhere between them. The same applies apparently to its toxicity to mammals. More extensive trials will be needed before the relative merits of these materials can be established and the best uses of “Velsicol 1068” defined. It is to be hoped that the structural formula of the compound will soon be published.