It has been long known that in various parts of Africa, the natives are in the habit of subjecting to the ordeal of poison parties who are suspected of crimes. On the east coast, we meet with Tanghinia venenata, yielding the Tanghin poison-nut of Madagascar; and on the west coast, seeds and barks of different kinds have been employed as ordeals,—the sources of which, however, have not been hitherto fully ascertained.

Dr Kirk, naturalist to the Livingstone Expedition, states, that the Manganja tribe, in the south-east of Africa, believe in a God, and in medicine, or the ordeal which he directs as the means of discovering crime. If the ordeal causes vomiting, it shows innocence; if it acts by the bowels, crime, and the person is put to death. But the doctors have a good knowledge of which to give, for there are different plants used.

In a former communication to the Royal Society of Edinburgh, I gave an account of an unusual fall of rain in the Lake District in the month of January last year. That occurrence was followed by its opposite in May, June, and July; not for a long period, not since 1826, has the district suffered more from want of water than in those months.

This drought is best shown by the following table, in which will be found the rain-fall for the several months of the year at five different places, only a few miles remote from each other. The table will also show the remarkable contrast as to excess and deficiency of rain during the period. It may be premised, that at Ambleside, where the drought appears to have been felt as much as anywhere, the ordinary fall of rain for the months in question is about three times as great; thus for May (our driest month of the twelve), taking the average of the preceding eleven years, it is 2·37 inches, for June 4·22 inches, for July 5·27 inches, making a total of 12·36 inches, against 4·54 inches of the months of drought.

In the writings of comparative anatomists, considerable difference of opinion is expressed respecting the position and relations of the thyroid gland in the Cetacea, and some authorities even have asserted that it does not exist in these Mammalia.

John Hunter states that he has examined several porpoises, balænæ, and other cetacea, yet “could not observe anything like a thyroid gland.”

Meckel believed that he found, in a fœtal porpoise (D. phocœna), eight inches long, a thyroid gland. He describes it as half an inch broad, two lines thick and high, and of equal depth and thickness both on the middle and sides of the air-tube, in the same position as that in which the gland is found in other mammals. From this examination, however, of so young a fœtus, he does not feel disposed to affirm that, contrary to the opinion of Hunter, it exists in full grown cetacea. In a subsequent paper he mentions incidentally, that in the dolphins the gland is formed of two quite separate lobes. Cuvier states that he has found the gland very distinct in many dolphins and porpoises. In these animals it was divided into two parts, and suspended from the trachea opposite the upper border of the sternum, and some distance from the larynx. Carus describes the gland in the dolphin and porpoise as consisting of two parts, entirely separate from each other. It is difficult to say, however, from the text, whether he is giving the result of his own observations, or simply adopting those of Cuvier. Dr Martyn repeats the statement that the cetacea do not possess a thyroid, and he ascribes the supposed absence of the voice in these animals to the want of this glandular structure.

1. The late Mr Alexander Adie, optician, and Fellow of the Royal Society of Edinburgh, was so generally known to be a zealous and careful observer of meteorological instruments, that an attempt to combine the results deducible from his labours carried on (though with one long break) over more than forty years, cannot be otherwise than interesting.

2. The plan of superintending the careful reduction of the thermometrical part of Mr Adie's registers occurred to me a long time ago, but circumstances prevented the execution of it until two or three years since, when, through the kindness of Mr Adie and his family, the whole of the manuscript observations, commencing with 1795, were put into my hands, and the Council of the Royal Society of Edinburgh provided sufficient funds for the employment of computers for reducing them.

3. The work has proceeded with frequent interruptions, but is at length complete. Before I proceed to detail the particulars of the reductions and their results, I will give a short account of the earlier observations on the climate of Edinburgh which I have been able to trace, some of which perhaps have hitherto escaped notice.

1. When I found that the interesting meteorological register of Mr Adie, which is well fitted to throw light upon the climate of Edinburgh, and of Scotland generally, was deficient of the important period of nearly sixteen years, from 1805 to 1820, I set on foot inquiries as to the existence of any other register of the thermometer which might approximately supply the defect. After some unsuccessful attempts, my attention was directed by Professor Dove's useful temperature tables to a register of the thermometer kept by the Rev. Mr Fergus of Dunfermline, of which the monthly means, from 1805 to 1824, are given in the “Edinburgh Philosophical Journal,” vol. xiii. Though the distance of Dunfermline from Edinburgh is thirteen miles in a right line, and though it occupies the opposite slope of the valley of the Forth, not far from the Ochil Hills, yet a slight comparison of the observations showed a very remarkable coincidence in its climate with that of Edinburgh, not only as regards the mean annual temperature, but also in the distribution of temperature throughout the year. I therefore made an effort to obtain the original register from which the results published in the “Edinburgh Philosophical Journal” were derived; and through the kindness, in the first instance, of Mr David Laing of the Signet Library, I was brought into communication with the Rev. John Fergus of Bower, near Wick, in Caithness, son of the Dunfermline observer, who most kindly placed in my hands his father's original register of the barometer, thermometer, and weather at Dunfermline, extending from 1799 to the time of his death in 1837, all made with one instrument, and at the same hour daily (9 a.m.), with very remarkable regularity.

By means of my correspondents abroad, and more particularly through the kind offices of Dr Christison, I have been enabled from time to time to cultivate in the Botanic Garden some of the rarer plants of the Materia Medica. Several of these, such as the Jalap plant, the Quassia, and the Aconitum ferox, have been already described and figured by me. The present is an interesting addition, and at the suggestion of Dr Christison I have brought it under the notice of the Royal Society.

The constitution and properties of the essential oils attracted considerable attention during the earlier period of the investigations in organic chemistry, and several of them have contributed in no small degree to the development of the general doctrines of that department of the science. A majority of these substances, however, may be said to be still almost unknown, all the information we possess regarding them being restricted to a single analysis, made on what was obviously a mixture, or to a few observations of a general and often indefinite character. The complex nature of many essential oils, and the want of experience and easy processes for the separation of their constituents, have hitherto deterred chemists from attempting their minute examination, but the progress of the science has increased our knowledge of the methods of investigating these substances, and renders it important that their true constitution and position in the chemical system be definitely fixed. With this object I have taken up the investigation of Oil of Cajeput; our information regarding which is confined to a single analysis made by Blanchet and Sell, some five and twenty years ago.

In this paper I shall first refer to the circumstances under which the following observations were made.

I had gone in the autumn of 1856 for a few weeks to Elie on the Fife coast, and was induced, as a means of relaxation and exercise in the open air, to pay some attention to the geology of the neighbourhood, resuming for a brief interval what was once a favourite pursuit. About a mile to the east of the village, I found a stratum well deserving attention—a thin bed of limestone—dipping inland a little beyond the cliff on which stands the ruined Castle of Ardross. The fossil shells which it contained were of unusual form, and beautifully preserved; there were fish remains of two or three species, and a small group of crustaceans still more remarkable. Among the fish I thought I could detect the large scales of an Irish species—the Holoptychius Portlockii—and among the crustaceans there were the valves of Dithyrocaris, a genus particularly characteristic of the Irish beds. At once the question arose whether these fossils might not serve as links connecting this Ardross bed with the Irish series. The point was of the more importance, that our leading geologists had been differing widely as to the true position of our Scottish coal strata in the geological scale. The lamented Professor Edward Forbes had assigned them a place comparatively high, while Sir Roderick Murchison, with surer judgment, had taken the opposite view and put them beneath the Newcastle coal-field.

1. Every purely periodical function is, as is well known, expressible by means of a series of constant coefficients multiplying sines and cosines of the independent variable with a constant factor and its multiples. This important truth was arrived at by an admirable piece of mathematical analysis, called for by Daniel Bernouilli, partially given by La Grange, and perfected by Fourier.

A few years since I was engaged in the performance of some calculations under the direction of Professor W. Thomson of Glasgow, having reference to the observations of underground temperature made at the Royal Edinburgh Observatory. In this paper I propose to describe a modification of Professor Thomson's method, which, while retaining a sufficient degree of accuracy, will be simple enough for general adoption. The objects proposed are—

1st, To express the variations of temperature at a given depth in terms of the time of year.

2d, To deduce the conducting power of the soil.