The diamagnetic susceptibilities of mixtures of benzene-acetone, chloroformacetone and nitrobenzene-acetone have been studied at different temperatures ranging from 15°;C to 50°;C, using the Quincke method with very large magnetic fields. The factors influencing the measurements made by such a method are critically considered and natural explanations are offered to the anomalous results obtained by different investigators. The susceptibilities of these mixtures obey the additive law in this range of temperature. Further the pure liquids do not show any variation in their susceptibility values between 15°;C and 50°;C. A large amount of evidence is presented to show that association in organic liquids does not produce any change in the specific susceptibility and that the additive law of mixtures is true unless chemical combination in the mixture changes entirely the nature of the bonds linked to the carbon atom.

Solutions of sulphur in carbon disulphide and sulphur monochloride have been studied by the Curie method. Small deviations of the order of 1 per cent, have been observed for solutions in carbon disulphide. This has been attributed to the breaking down of S₁₆ molecule. No evidence has been obtained to indicate the presence of S₂ in sulphur monochloride solutions. A few halides of sulphur have also been investigated. The results throw useful light on the valency of sulphur in the different compounds.

We take this opportunity of thanking the authorities of the Annamalai University for the award of studentships which enabled us to undertake this investigation. Our thanks are also due to Dr. S. Ramachandra Rao for his interest in this work.