L'hiver passé je reçus une invitation de Sir John Murray à venir, en qualité d'assistant, au Challenger Office étudier sous sa direction une nombreuse collection de concrétions phosphatées et nodules provenant de dépôts dragués par les bateaux du “Department of Agriculture” du Cap de Bonne Espérance et envoyée par Dr J. D. F. Gilchrist, “Government Biologist of the Cape of Good Hope.”

In scientific literature the evaporation of musk has a considerable interest. Almost every writer on the divisibility of matter cites it as an instance of the extremely minute division of which matter is capable, our sense of smell enabling us to detect a more minute quantity of this form of matter than can be detected of any other kind of matter by any of the modern refined methods, such as the spectroscope, or chemical processes. It is possible we may shortly have to modify this statement, as extremely small quantities of some kinds of matter can be detected by their radio-activity; but, so far as I know, no reliable numerical values have been obtained in this direction.

The apparatus used to show that aluminium was opaque to the ions from a flame consisted (see fig. 1) of a tube A, which was

funnel-shaped at one end, the other end of which led to an enclosure B, one side of which (a b) was made of aluminium foil connected to earth, and on the other side there was an insulated metallic plate (c d), which could either be connected to earth or to a high potential battery. On the other side of the aluminium foil there was an electroscope in a closed case C. The electroscope was of the type used by C. T. R. Wilson in his experiments on the natural ionisation of air in closed vessels.

The nature of the connection of this with the theory of determinants is evident from the title. Some of the elementary portions of the memoir had in fact already appeared in Cauchy's determinant papers of the years 1812, 1840, 1841, and have been noted in our accounts of the latter. In these papers, as was natural, only such isolated properties were given as might be of immediate application to the main subject: here we have a methodically arranged and lucidly written treatise. As, however, in dealing with permutations the question of signature is not taken up, there is no explicit reference to determinants: and all that is therefore necessary is to direct attention to a storehouse of information regarding a subject closely connected with them.

The following beliefs regarding vision meet with very general acceptance:—

First. Very intense light of any wave-length produces practically the sensation of whiteness.

Second. Very weak light of any wave-length produces practically the sensation of whiteness.

Third. A coloured area of normal brightness retains its colour, though with diminished purity, when gazed at steadily for a long time.

Fourth. Small, faintly luminous, objects are seen more easily by indirect vision than by direct vision.

In the course of a research on the boiling points of aqueous solutions, certain points came under my notice which have been introduced into this note.

After considerable experience with various forms of Beckmann's boiling point apparatus, and due consideration of the Jones type, a boiling point apparatus was designed which embraced what were considered the best points of each, in view of the research anticipated. The body of the tube was of the Jones type, and had a side tube fitted with a rubber stopper for the introduction of the salt at a short distance from the top of the tube. On the opposite side of the boiling tube, about the same height up, went off a condensing tube of the Beckmann pattern. The thermometer—one of Beckmann's—read to hundredths of a degree, and, with the aid of a Beckmann reading glass, could be estimated to thousandths of a degree. It passed through a close-fitting rubber stopper at the top of the tube.

In this contribution an account is given of the dominant plants of aquatic and semi-aquatic habit existing in and about the lakes of the following districts of Scotland:—

1. The Loch Ness area.

2. The lakes in the Island of Lismore, Argyll.

3. Lakes situated between Nairn and the Culbin Sand Hills.

1. The gradual growth of the theory of molecular magnetism from the original suggestions of Poisson and Weber is well known. The recent great development, made by Ewing, and tested experimentally by means of models, has placed the theory on a fairly firm basis, and has made essentially secure the fundamental postulate that magnetic phenomena in material bodies are due to magnetic molecules which may possibly be regarded as free from any directional control other than that supplied by their own mutual action.

§ 65. Referring to § 63, we must, for the present, as time presses, leave detailed interpretation of the curves of fig. 17: merely remarking that, according to § 44, if δ=0, (which means that J is an integer), the disturbance, d, is infinitely great; of which the dynamical meaning is clear in (70) of § 39.

The ventricular rhythm differs from the auricular, firstly, on the occurrence of a ventricular extra-systole, and, secondly, in cases where there is allorhythmia due to depression of conductivity of the heart muscle. When conductivity is depressed, the contraction stimulus at regular or irregular intervals may be blocked at the auriculo-ventricular muscle bridge; so that whereas some stimuli induce both auricular and ventricular systole, others induce auricular systole alone, the ventricular systole being missed. That condition, incomplete heart-block, is of not infrequent occurrence in the human heart, and has been graphically recorded by Mackenzie (1), Finkelnburg (2), and other writers.

During the last five years the greater part of my time has been taken up by the study of the plankton in the fresh-water lakes of Denmark, and in the spring of 1904 the first part of an extensive paper upon this subject was published by me. In that paper I have compared the results arrived at by me with the results of plankton explorations in other countries, and have tried to collect together everything known at the present moment regarding the periodicity and geographical distribution of the European freshwater plankton.