Analysis of the dredgings brought to the surface during the Voyage of H.M.S. “Challenger,” has shown, that in deeper water as the depth increased, the quantity of carbonate of lime shells decreased,* and as the pressure is in direct proportion to the depth under water, it was surmised that some connection existed between the pressure and the disappearance of lime shells. To ascertain if there was any truth in this surmise, Mr Murray suggested the following experiments. The results are unfortunately incomplete; nevertheless, Mr Murray thinks it advisable to publish them.

The results already obtained were got by means of a roughly made apparatus designed for the purpose of testing the method used, so that only a single instance, to show their general character, need now be given. When a wooden block of 10 lbs. mass fell through a height of 18¼14 inches on a rounded lump of gutta-percha, the time of impact was found to be somewhere about 0.001 sec, and the coefficient of restitution was 0.26.

In the second and third numbers of the ninth volume of Tschermdk's Mineralogische und petrographische Mittheilungen, I published the results of an examination of some “dolerites” from the Carboniferous basin of the Firth of Forth, the material for which I obtained through the kindness of Prof. Archibald Geikie. It is true most of the “dolerites” are already well known through the valuable writings of Professor A. Geikie and Mr Allport, but a special study of the modifications of the rock in the different parts of any one volcanic mass has not yet been the subject of any paper. Having elicited many facts of petrological interest, I purpose giving in this communication a short account of my investigations.

In the introduction it is pointed out that, although ciliary motion has been observed and noted in the mussel, independent locomotion communicated to the gill itself has not yet been studied, and it is pointed out that a sea-mussel when detached is capable of roaming about—can float and can sink.

In the present paper I propose to give the result of my examination of the specimens of fishes which were obtained by Mr John Murray on the West Coast of Scotland, whilst dredging during the last eleven months on board of the “Medusa.” Exact observations as to the bathymetrical distribution of British fishes at certain seasons and localities, such as have been obtained during the cruises of the “Medusa,” are much needed, and if methodically carried out for some years, will prove a most valuable contribution to the British fauna, especially if they are supplemented by similar reports on the invertebrates which were collected simultaneously with, and form part of the food of, the fishe.

A grant was made by the British Medical Association, on the recommendation of the Scientific Grants Committee of the Association, towards the expenses of a research, a part of which appears in this communication.

There is general agreement as to the value of the quantity nv, which expresses the fraction of the whole group whose members have speeds from v to v + dv; and as to the corresponding Mean Path pv,. The “mean,” in this case, is found according to the definition given by De Morgan:—

An examination of the Birth Registers pertaining to the parish of Marnoch, in Banfishire, for the ten years ended 1886, exhibits the following startling results:

Koch, in his article on Disinfection and Antiseptics in the Mittheilungen aus dem K. Gesundheitsamte, vol. i., 1881, p. 264 (abstracted by Dr Whitelegge in the publications of the Kew Sydenham Society, vol. for 1886, “Microparasites in Disease”), gives the result of an elaborate series of experiments with mercuric chloride, and comes to the conclusion that a single application of a very dilute solution (1 to 1000, or even 1 to 5000) is sufficient to destroy the most resistant organism in a few minutes. He further states that, “with longer exposure, it only begins to be unreliable when diluted beyond 1 to 20,000.”

This will appear in the Transactions in Part III. of Prof. Tait's paper “On the Foundations of the Kinetic Theory of Gases.”

I had the honour of communicating to the Koyal Society of Edinburgh, upon the 15th July last, a paper describing a new difiusiometer. This instrument was devised to make visible to the eye the diffusion of acids or alkalies into a supernatant column of water.

So much for sails. Now I want to make some suggestions, or suggest some queries, as to the shimming flight of birds, in reference to which a good deal of fresh obsarvation has been possible during the voyage.

In this paper Mr Peddie described some preliminary experiments made on the resistance of dilute solutions of sulphuric acid (ordinary commercial). The solution is enclosed in a glass tube, which passes through a metal vessel containing water. Each end of the tube dips into a separate vessel containing some of the acid solution, and a platinum electrode is placed in each vessel. This apparatus is joined in circuit with a Helmholtz tangent galvanometer and a Brush dynamo. The current from the dynamo is then passed through the arrangement, and the water surrounding the tube is stirred constantly until its temperature ceases to rise. The temperature of the water, the temperature of the air, and the current strength are then noted, and the resistance is obtained by the application of Joule's Law, the rate of loss of heat being known.