Conclusions1 . The dependent variables A and Aq are .shown to be strongly temperature-dependent.2. The precision of the present technique is insufficient to indicate the influence of particle size on the dependent variables A, B and Aq, or the influence of temperature on B.3. The Warburg technique would be suitable for a major survey of coals to decide whether there is a correlation of reactivity and pyritic content, or a correlation of either with tendency to spontaneous combustion.Samples of matai (Podocavpus spicatus) essential oil from different parts of New Zealand are compared and shown to differ only in the terpene alcohol and diterpene constituents. The compounds identified in the oil are a-pinene, myrcene, a-terpinene, P-phellandrene, dipentene, y-terpinene, p-cymene, a-terpineol, aromadendrene. a selinene, cadinene and kaurene or phyllocladepe. The substance known as ' y-podocarprene' is a diterpene alcohol.