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.

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.

Telegraphic communication between-Ben Nevis Observatory and Fort-William Post Office is kept up by means of a line which consists of an ordinary telegraph wire from Fort-William to Auchintee Farm at the base of the mountain, and a cable laid underground from thence to the summit. At Fort-William the wire is put to earth in the usual way, while at the Observatory the return wire is attached to the iron-wire sheath of the cable.

When the compressibility of a liquid or gas is measured at very high pressures, the compression vessel has to be enclosed in a strong cylinder of metal, and thus it must be made, in some way, selfregistering. I first used indices, prevented from slipping by means of hairs. Sir W. Thomson's devices for sounding, at small depths, by the compression of air, in which he used various physical and chemical processes for recording purposes, led me to devise and employ a thin silver film which was washed off by a column of mercury. Much of my work connected with the Challenger Thermometers was done by the help of this process. Till quite recently I was unaware that it had been devised and employed by Cailletet in 1873, only that his films were of gold.

The foregoing paper was read on 5th July 1880. We postponed, however, its publication, feeling that however interesting the formation of the bodies therein described might be, much careful quanti tative research would have to be undertaken before any definite conclusion as to the true nature of these bodies could justifiably be drawn. Only the title of our paper was therefore published in the Proceeding of this Society. The old University Laboratory being in many respects'unfitted for the prosecution of accurate quantitative work, our researches were repeatedly postponed in the hope of being able to continue them in the new University Laboratory, which, however, only now approaches completion. This delay has been to us a subject of much regret, the questions involved being of no little interest.

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.

To appreciate the present position of biological science, it is necessary to have a clear conception of the history. For this, abundant historical materials are indeed available, and reach their highest level in the standard works of Sachs and Carus. Such detailed histories, however, produce, by their very completeness, a measure of embarrassment. Moreover, the existence of numerous distinct lines of research, often equally prominent at the same time and in the same work, is apt to obscure the fact that the science has really had a simple and natural evolution. What the student demands is not so much any detailed chronological survey, but rather a sketch which will show how the whole system of modern biology, with its increasingly exhaustive analysis of detail, lies within a few essential lines of research, as laid down by a definite succession of original thinkers.

As the result of Andrews' experiments on the boiling-points of substances, we have the law enunciated that There is a critical temperature for every vaporous or gaseous substance ; such that, only when its temperature is below this, can the substance be reduced to the liquid form by any pressure, however great. Similarly, a law may be laid down regarding the passage from the liquid to the solid state, or vìce versâ. Thus we may say that There is a critical temperature for every solid substance, which contracts in the act of liquefaction, such that only when its temperature is above this, can the substance be reduced to the liquid form by any pressure, however great; and for every liquid substance, which contracts in the act of solidification, such that only when its temperature is below this, can the substance be reduced to the solid form by any pressure, however great.

The author has recently been engaged in a variety of electrical observations in connection with wrought iron and steels, in the course of which it occurred to him to investigate some of the effects produced in the presence of nascent oxygen, of the ozone type, by a current of sufficient strength to readily decompose these metals by oxidation whilst immersed as electrodes in distilled water, the great resistance of the latter apparently facilitating the interesting results observed and recorded below.

A short time ago I published a method in the Chem. News, vol. liii. p. 41, “On the use of Hydrogen Peroxide as an oxidising agent for detecting and estimating Manganese;” showing the advantages it had over other sources of oxygen for oxidation purposes, simply on account of the fact, that when using hydroxyl you do not introduce any objectionable foreign substance, such as manganese, chromium, potassium, lead, &c.

The question as to the normal duration of the life of red blood corpuscles has hitherto been considered more as a matter for speculative inquiry than for experimental proof. Attempts have from time to time been made by various observers to solve it experimentally, by injecting the blood of one animal into the circulation of another, whose blood corpuscles were of different size and shape, and then noting how long the foreign blood corpuscles remained discoverable in the body of their host. As might have been anticipated, the success of such experiments has not been very striking.

The following results of observations made with four of the thermometer screens, devised by Mr Aitken of Darroch, form the commencement of an investigation which has been begun at Granton Marine Station, and which is to be carried on there and at Ben Nevis Observatory during the summer and autumn, with the view of finding a more suitable screen for exposing thermometers for meteorological purposes, and, if possible, of determining the mean correction to be applied to the readings of thermometers exposed in the ordinary Stevenson screens. So far, the work has been entirely of a preliminary character, but some points have been brought to light which are of considerable interest.

The temperature of water can be ascertained much more easily than that of air, and with far greater accuracy; yet comparatively little has been done by meteorologists in the way of obtaining data bearing on the distribution of temperature in rivers and in estuaries. Some observations of great value have been discussed by Mr Buchan in the Scottish Meteorological Society's Journal, but these were discontinued after a few years.