IN an assembly which included ministers of railways and of agriculture, professors of physics, cold-storage engineers, fishery experts, fruit importers, and traffic managers, one naturally expected a very varied type of communication. A considerable portion of the available time was.devoted to questions of such general importance as the settlement of units and the various legal matters in which cold storage, transport, and similar questions are getting involved. There were also a large number of purely scientific papers dealing with the production of cold, the determination of conductivity, and similar problems. Prof. H. K. Onnes gave, by special request, an account of his recent work on hydrogen and helium. He was followed by Prof. Mathias, who pointed out that, in the determination of the critical volume by his well-known straight-line law, substances did not follow, as a whole, the law of corresponding states. However, when divided up, into groups, the correspondence was very perfect in the group. Prof. Onnes expressed the view that the divergencies must be ascribed to a difference of compressibility of the molecules themselves, or to a different distribution of potential round them. M. R. Pictet opposed strongly the view of ascribing an apparent volume to the.molecules, and gave an interesting paper on the uses of low temperatures.