The various forms of apparatus employed for procuring samples of water from beneath the surface are either designed to take up as a sample a mixture of the water in a certain vertical range, or to secure their entire charge at one definite position. The former description of water-bottle has been used almost invariably in deepsea work; the latter is necessary only in shallow water.

The shells of certain molluscs which are obtainable on the seashore between tides are seen to be more or less coloured green. I have noticed a fine rich colour on the operculum of a Turbo from the Pacific Ocean, which had been killed and the shell preserved dry. The shell has a high polish, the colour is the rich green of an ivy leaf, and the pigment is contained in the shell material. When the mollusc dies, and the shell is left exposed to air, light, and water, the green becomes a brownish-yellow colour. Some specimens of spirit, which had been poured off shells and fragments of coral obtained by dredging in deep waters, were examined by me for Mr J. T. Buchanan.

My object in this paper is to call attention to a few observations which occurred to me during a recent scientific survey of part of Central Africa, regarding the larger economy of tropical nature. And I wish especially, and with much deference, to attempt to supplement a well-known theory of Mr Darwin's, by bringing forward another claimant to the honour of being, along with the earth-worm, the leading organic agricultural and geological agent in nature.

In connection with the observations carried on by one of us on the salinity and temperature of estuaries, it seemed desirable to examine the condition of the water near the mouth of a river flowing directly into the sea. For this purpose it was necessary to select a stream of considerable volume and free from pollution.

It is a familiar fact that the heart of cold-blooded vertebrates may continue to beat for a long period–even for days–after its removal from the body, but it is not so well known that contractions may occur in the heart of the higher vertebrates for a considerable time after death. On this latter point, however, there are many observations on record. Harvey noted that rhythmical contractions continued in the heart of the pigeon for some time after death, and, further, that after it had ceased to beat, it recovered its vigour, and both auricles and ventricles pulsated on the application of a stimulus, such as the tip of the finger wetted with saliva.

The recent extensive therapeutic use of cocain has naturally aroused great interest with regard to its chemical constitution. As is well known, when heated with dilute mineral acids, it takes up two molecules of water, and becomes decomposed into benzoic acid, methyl alcohol, and another alkaloid ecgonin. When cocain, however, is simply heated in watery solution for some hours, a less complete decomposition ensues, the solution depositing on evaporation a crystalline substance, which is benzoylecgonin.

In a memoir published in the Chemical News, vol. xlviii. Page 37, and the Journal of the Chemical Society, 1884, page 94, I gave some account of a peculiar excretory product found in the Sepia's “liver.”The product was found to be albumin in pseudo-crystalline aggregations when examined under the microscope. These bodies are not of a constant occurrence in this organ of the Sepia. Since the publication of the above paper, which is a year and a half ago, I have made a thorough examination of this organ in Sepia, which substaniate and extend the observations of Krukenberg, Fredericq, and Jousset de Bellesme.

I will commence my paper with a brief description of the typical characters of a reef in this region, referring particularly to the distribution of the corals. There would appear to be a large number of new specific forms among the reef-corals of these islands, whether hydroid or actinoid. Out of nearly seventy species that I sent to the British Museum, almost a quarter are new or undescribed; and there is every probability that similar success will fall to the lot of other collectors in these seas. There is yet much to be learned of the fauna of the deeper parts of the reef-coral zone; and patient dredging will doubtless yield fruitful results. Here, not improbably, will be found the corals of deep-sea genera and the Rhynconella that I discovered in an upraised barrier-reef in the Shortland Islands. Having only a small canoe, I was not able to dredge in these depths; but I may remark, as a good omen for others, that, when sounding off a reef on one occasion, I brought up from a depth of 14 fathoms a new and very distinct species of Distichopora (D. ochracea), which is described and figured by Mr J. J. Quelch in the Annals and Magazine of Natural History for July 1885.

The second, only, of two short papers which I communicated to the Society a month ago, on points connected with the Kinetic Theory of gases, took account of the greater probability of collision between two particles as their relative speed is larger. I propose now to calculate the effect of this consideration on the results of my first paper.

This paper contained an account of the experimental evidence in support of the theory of solution enunciated in a paper “On the Nature of Solution,” communicated to the Society in January 1883. Solution of a salt in a liquid is a consequence of the attraction of the molecules of the liquid, for a molecule of the salt (adhesion), exceeding the attraction of the molecules of salt for one another (cohesion). As the number of dissolved salt molecules increases, the attraction of the molecules of liquid for the molecules of salt becomes more and more balanced by the mutual attraction of the salt molecules. When these two forces are in equilibrium, saturation ensues.

During the spring of 1882 Mr Burton and I communicated some preliminary experiments on a new method of measuring the heats of combination of the metals with the halogens.

The results of more than a year's study of the distribution of micro-organisms, that is, bacteria and fungi in water, are I think of sufficient interest to justify a short communication.

The ever-increasing importance of nitrites in medicine, owing to their power as therapeutical agents, and to the scientific work which has been and is being done to elucidate their pharmacology, renders a knowledge as to the precise amount of nitrite a commercial specimen contains of high, importance. For while to most patients a dose of five or six grains of pure, or nearly pure, nitrite of sodium is as large a quantity as they can conveniently bear, we read of twenty and thirty grains of so-called nitrite of sodium having been administered without dangerous or very unpleasant results. In such cases we cannot but conclude the drug was impure, and MacEwan has shown that samples of nitrite of sodium were met with in commerce containing but a decimal percentage of the salt. Many papers have recently appeared on the estimation of nitrite of ethyl in the spirit of nitrous ether, but in this contribution I desire only to consider those methods suitable for the estimation of nitrous acid in its inorganic compounds.

Among the many interesting genera of earthworms described by M. Perrier, the most interesting and remarkable in many ways is Eudrilus. This genus is unique among earthworms, by reason of the peculiar structure of its generative organs. In all earthworms at present known, with this exception, the ovaries are situated in a distinct segment of their own, into which opens the funnel of the oviduct, which is quite independent of the ovary; the oviducts generally pass through the mesentery which bounds posteriorly the segment (usually the 13th) containing the ovaries, and open on to the exterior of the body in the ventral surface of the following segment.