As

action in the sun on cometary matter, and other facts adduced by the "Wrangler," all point to the conclusion that the laws we are acquainted with do not explain the whole system or cosmos. the "Wrangler's" paper is only a pamphlet of fifty-six pages, we abstain from extracts, merely recommending it to the notice of those who like to see inquiry stimulated, and the best established beliefs re-examined from time to time.

NOTES AND MEMORANDA.

THE COLOUR OF WATER.-Father Secchi, in a paper on "Star Spectra," in "Comptes Rendus" (1867, No. 14), says: "Having ascertained that the spectrum of sea-water is destitute of red at small depths, and of yellow and green-at least of their greater part-at successively greater depths, at which the water has a blue or violet colour, I wished to see if the same absorptions were exhibited in glaciers. Profiting by the incident of an artificial grotto having been dug in the glacier of Grindelwald, I made some experiments on this subject. The grotto in question is about 100 metres deep, its walls are transparent, and illuminated by sunshine passing through the ice. This light has a fine blue tint, in which the red is extremely weak, so that in the grotto human faces have a frightfully cadaverous aspect. Looking from a certain depth in this grotto back towards the entrance, the light there appears red, owing to the effect of contrast. A spectroscopic examination shows the light in the grotto to be almost deprived of red, and to have the yellow greatly diminished. The thickness of the ice is not sufficient to produce a more complete absorption. It is said to be about fifteen metres thick, but I should say less. The ice is perfectly compact and continuous in its texture. It is limpid as crystal, and contains here and there groups of air bubbles. Its hardness is not great; an iron point easily penetrates it. The result is thus identical with that which is obtained with sea-water at similar depths; and as in the Alpine ice we cannot suppose the presence of extraneous colouring matter that might be presumed to exist in the sea, it follows that the true colour of water is a blue mixed with violet, which grows darker as the thickness traversed by the light increases."

SULPHURIC ACID FORMED BY A MOLLUSK.-M. M. S. de Lucca and P. Panceri state, in "Comptes Rendus" (1867, No. 14), that the salivary organs of the Dolium galea secrete a fluid which contains more than three per cent. of sulphuric acid. They examined two specimens caught in the Gulf of Pozzuoles. When filled with liquid, the glands, two in number, are larger than ordinary fowls' eggs, and weigh about seventy grammes. They are formed of two distinct parts-one small and opaque, close to the excretory orifice of the gland; the other large and transparent, the membrane enveloping it being very thin and white. When incisions are made, so that the lower part of the gland comes in contact with the air, gaseous bubbles of pure carbonic acid are disengaged from the cul de sac tubes, of which almost all the gland is composed. A gland weighing seventyfive grammes discharged under water 200 cubic centimetres of carbonic acid. The liquid contained in the gland tastes like lemon juice, acts on marble, and changes the colour of litmus. A series of experiments show it to contain sulphuric acid. It was previously known that the Dolium galea ejected an acid liquid from its mouth which effervesced with carbonates, and when analysed by M. Bædeker, gave 2.7 per cent. of sulphuric acid. The authors of the paper state that they will continue their researches with a view to discover how the sulphuric acid is produced, and what function it performs in the economy of the animal. They say this Dolium "is the first animal which they knew of capable of making sulphuric acid by an unknown process."

THE COLOUR QUESTION AND THE LUNAR ECLIPSE, SEPT. 13TH.-Referring to the accounts of this eclipse we published in our last number, we may say that

several observers besides Mr. Browning speak of absence of colour. M. Chacornac states the contrary. He says the greater part of the lunar disk plunged into the shade of the earth was of a red colour, the portion near the limit of the shadow slightly violet. Between these two extremes, yellow, orange, green, and blue exist, resulting from the decomposition of solar light by refraction of the terrestrial atmosphere. Mr. Huggins informs us that excess of light prevents a proper view of colour, and Mr. Knott has found too much light to interfere with a just appreciation of the tints of double stars. M. Chacornac's observations were made at Ville-Urbanne, but he does not say with what aperture. He has the large Foucault reflector there. The "Monthly Notices" contain Mr. Weston's observations made at Endsleigh Observatory, Bath. He describes the prevailing colour as “red-bluish and grey, and grey. The redness increased towards the darkened edge of the moon. He did not notice this colour at "the boundary line when the earth's shadow impinges on the moon; but, on the contrary, it was confined to the opposite eclipsed region, darkening as it approached the northern parts, and attaining the greatest depth at the moon's periphery.... That these effects did not result from any chromatic errors was proved by using different telescopes and powers. The colour and their relative positions differed entirely from those presented in the partial eclipse of Feb., 1858."

TWO NEW PLANETS, (93 and 94 - -Mr. Watson, of Ann-Arbor, states in the "Astronomische Nachrichten," that he discovered the first of these bodies on the 24th August, and the second on the 6th Sept. Both are of 11 mag.

MICRO-CRYSTALS OF ALKALOIDS.-At the meeting of the Royal Microscopical Society, on the 9th Oct., Dr. Guy read a long paper on crystallizations and arborescent forms obtained by subliming minute quantities of strychnine and other alkaloids in the manner originally proposed by Helwig. Dr. Guy's process is to place the matter to be sublimed at the bottom of a small flat porcelain vessel, such as a crucible cover. Over it he puts a square of glass, about one-eighth of an inch thick, with a round hole in the middle. Over this hole he places a flat piece of glass. A moderate heat, carefully applied by a spirit lamp, sublimes the alkaloid, and it is condensed on the plate of flat glass, and ready for microscopic examination. Quantities such as the 10,000th part of a grain give satisfactory results. Many photographs of crystallizations, exhibited by Dr. Guy, were of great beauty. Evidence of this kind might be important in medico-legal inquiries, but it could scarcely be regarded as conclusive, though it might form part of a conclusive chain of proof.

THE COMING STAR SHOWERS.-Our readers should refer to the important paper by Mr. Proctor, in our last number, on this subject, before the arrival of the 14th. At a quarter past six on the morning of the 14th may be the maximum, but the meteors should be looked for some hours earlier to prevent disappointment.

A WAISTCOAT-POCKET MICROSCOPE. — The most elegant and convenient portable microscope is one devised by Mr. Highley, on the plan of the class microscopes introduced by Dr. Lionel Beale. Mr. Highley's instrument fits into a German silver case, rather less than four inches long and five-eights of an inch wide. It is furnished with a live-box, draw-tube, eye-piece, and dividing objec tive. Its power is sufficient to show the nature of urinary deposits and other morbid products; and as a field instrument for the collector of diatoms, desmids, minute algæ, etc., it will be highly esteemed.