satisfactorily accounted for, except in some measure by Dr. Withering, who has ascribed them to the growth of agaric. His remarks, however, were confined to one species of agaric, the Ag. orcades of his arrangement; but Dr. Wollaston has observed that these rings are formed by the growth, not merely of this agaric, but also of the common mushroom (Ag. campestris), the Ag procerus, and the Lycoperdon bovistu. In the case of mushrooms, he found them solely at the exterior margin of the dark rim of grass; and he was led to conjecture from their position, that progressive increase from a central point was the mode of formation of the ring.

We do not conceive it worth while to dwell upon this theory for, in truth, we do not regard it as satisfactory. The most plausible theories, beside this, are those of Mr. Gough, and M. Florian-Jolly, which are detailed in Nos. 50 and 51 of Nicholson's Philosophical Journal, or No. 4 of the Retrospect of Discoveries.

VIII. Observations on the Structure of the Stomachs of different Animals, with a view to elucidate the Process of converting Animal and Vegetable Substances into Chyle. By Everard Home, Esq. F. R. S. Read April 13, 1807.

Mr. Home's observations on the stomachs of the porpoise and of ruminating animals, described in former communications to the Royal Society, inclined him to believe that the fourth cavity of the ruminant's stomach, while the animal is alive, is always divided, in a greater or less degree, into two portions, one of which includes the plicated structure, the other the villous. Hence he was led to conjecture that the food undergoes two changes in the stomach, the one preparatory to the other; the last of these forming the chyle. In order to investigate still further this curious subject, he has examined the internal structure of the stomachs of different animals ; and the results of his inquiries are now laid before the Royal Society.

Mr. Home describes the internal structure of such stomachs as appeared to form the principal steps in the gradation between animals which ruminate and those which are truly carnivorous, arranging them in a series, the beginning of which is that nearest allied to the stomach of the ruminant in the complexity of its parts, and the termination, that which is most simple in its internal structure. Our indefatigable anatomist states that he derived material assistance in the course of his inquiries from Mr. Brodie, and that the extremely accurate drawings accompanying the paper were made by Mr. W. Clift. The subjects, whose stomachs he examined, were the turkey, the cod-fish, the hare, the beaver, the dormouse, the water-rat, the common rat, the horse, the ass, the kanguroo, the hog, the

pecari, the elephant, the mole, the stoat, the armadillo (with nine bands); he also examined the human stomach, and that of the lynx, the vampyre bat, the long-eared bat, the hawk, the cormorant, the viper, the turtle, the frog, and the blue shark.

It will not be expected that we should follow Mr. Home in his details respecting the stomachs of all these animals: those who devote their attention to anatomy and physiology, will read with pleasure and advantage the whole paper; while to the general reader we shall present Mr. Home's summary of the principal results, as below:

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From the series of facts and observations which have been adduced, the following conclusions may be drawn.

That the solvent liquor is secreted from glands of a somewhat similar structure in all animals, but much larger and more conspicuous in some than others.

That these glands are always situated near the orifice of the cavity whose contents are exposed to their secretion.

That the viscid substance found on the internal membrane of all the stomachs that were examined recently after death, is reduced to that state by a secretion from the whole surface of the stomach which coagulates albumen. This appears to be proved, by every part of the fourth cavity of the calf's stomach having the property of coagulating milk.

This property in the general secretion of the stomach, leads to an opinion, that the coagulation of fluid substances is necessary for their being acted on by the solvent liquor; and a practical observation of the late Mr. Hunter, that weak stomachs can only digest solid food, is in confirmation of it.

That in converting animal and vegetable substances into chyle, the food is first intimately mixed with the general secretions of the stomach, and after it has been acted on by them, the solvent liquor is poured upon it, by which the nutritious part is dissolved. This solution is afterwards conveyed into the pyloric portion, where it is mixed with the secretions peculiar to that cavity, and converted into chyle.

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The great strength of the muscles of the pyloric portion of some stomachs, will, by their action, compress the contents, and separate the chyle from the indigestible part of the food.

In animals whose food is easy of digestion, the stomach consists of a cardiac and pyloric, portion only; but in those whose food is difficult of digestion, other parts are superadded, in which it undergoes a preparation before it is submitted to that process. pp. 177, 178.

IX. Experiments for investigating the Cause of the coloured concentric Rings, discovered by Sir Isaac Newton, between two Object-glasses laid upon one another. By William Herschel, LL.D. F.R.S. Read Feb. 5, 1807.

This is a very long, very ill-arranged, and very uninteresting paper, though on a highly curious topic. We are disposed to treat every communication from this distinguished astrono mer, with all due respect; but several of the papers he

has recently published have been so feeble and jejune, that we really fear his reputation as a philosopher is liable to a degree of injury from his own ill-directed and imperfect labours, which it could not apprehend from any other source. The doctor's present object seems to be, to overturn the Newtonian theory of fits of easy transmission and easy reflection. Without desiring to be considered as strenuous advocates of that hypothesis, we may venture to say that he has not advanced one argument, in this communication, by which the probability of the existence of those fits is in the smallest degree lessened. For though he affirms that, when a lens is laid upon a metallic mirror, there is no transmission of the rays; yet the absorption, which he is not unwilling to admit, is in fact to be considered as a species of transmission. As a careful astronomical observer, and an ingenious experimenter, Doctor Herschel deserves much praise: but of late he has generally commenced his investigations before he has acquainted himself with what had been done by other philosophers, or else has abandoned them before they have produced any results of real importance. As far as we can judge from the paper before us, Dr. Herschel, seems to have confined his study of the phenomena of light almost entirely to the works of Newton; as though nothing worthy of his notice had been done in the compass of a century, the most momentous ever known with regard to the progress of philosophical discovery. Is it possible that this able astronomer should never have heard of Euler, of Bouguer, of Varignon, of the abbé Mazeas, of Boscovich, of Jordan, of M. Young, or of T, Young? Or does he think that none of these philosophers have made discoveries worthy of his attention, respecting the colours of thin plates? Finding him to have been so extremely ill prepared for the study he undertook, we are not surprised that he should speak of the colours of thin plates as the discovery' of Newton, through ignorance of the previous observations of Dr. Hooke and Lord Brereton; nor can we wonder at his hasty conclusion, that the subject of these modifications of light has been 'totally overlooked' by all later authors. We hope that be fore this gentleman farther prosecutes the subject in the way he proposes, he will take the pains to learn what has been done already, and thus spare himself the mortification of baving laboured unnecessarily and in vain.

Considering the natural tendency of a high reputation to give currency even to very indifferent reasonings, we have thought it right to express our decided opinion on the present occasion. So far from the pretty experiment described by Dr. H. (p. 231) being decisive against the Newtonian hypo

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thesis, as we have lately heard it pretended, we consider it as totally unconnected with the question. Because the rays o light are found to undergo certain flexions and modifications in the neighbourhood of bodies near which they pass when converging from the surface of a mirror, does it follow that they are not liable to other modifications at the surfaces of transparent bodies ? Tiei would be a curious way of refuting the position that 2 and 3 make 5, to affirm, though ever so gravely, that 8 and 9 make 17: Propositions may be different without being contradictory. The colours here described are identical with those of the corona described by M. Jordan and others, and certainly have no immediate connection with the colours of thin plates.

X. On the Economy of Bees. In a Letter from T. A. Knight, Esq. F. R. S. to the Right Hon. Sir Joseph Banks, Bart. K.B. P. R. S. Read May 14, 1807...

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According to this paper, the opinion, that each hive or swarm of bees remains at all times unconnected with other colonies in its vicinity, is erroneous; for Mr. K. found that a friendly intercourse often takes place between different colonies, and that this not unfrequently' ends in a junction of the two swarms. He also remarked that bees will ، carry other things on their thighs' beside the farina of plants with which they feed their young; and he is strongly disposed to believe that' bees-wax, instead of being an animalsub stance exuding between the scales of the insect's belly, as Mr. Hunter imagined, ، is collected from plants, and merely deposited between' those scales. Beside the preceding observations, there is nothing worthy of notice in this paper ; except the frequent recurrence of the term "not unfrequently, a fashionable phrase, we conjecture, with the dilettanti part of the R. S., importing nearly the same as frequently, or often. Those who want to learn any thing, important relative to the economy of bees, will obtain far more information from M. Huber's Nouvelles Observations sur les Abeilles, than from a hundred such hesitating, indecisive, unfinished communications, as that which we are now dismissing.

XI. Observations and Measurements of the Planet Vesta. By John Jerome Schroeter (of Lilienthal) F. R. S. Read May

28,

1807.

This is a modest, unassuming paper, neither giving, nor pretending to give, much information. M. Schroeter finds that the apparent diameter of the planet Vesta is only 0.488 of a second, and only half of what he has found to be the apparent diameter of the fourth satellite of Saturn.. He then adds,

• This extraordinary smallness, with such an intense, radiant, and unsteady light of a fixed star, is the more remarkable, as, according to the preliminary calculations of Dr. Gauss, there can be no doubt that this planet is found in the same region between Mars and Jupiter, in which Ceres, Pallas, and Juno perform their revolutions round the sun; that, in close unión with them, it has the same cosmological origin; and that as a planet of such smallness and of so very intense light, it is comparatively near to the earth. This remarkable circumstance will no doubt be productive of important cosmological observations, as soon as the elements of the new planet have been sufficiently determined, and its distance from the earth ascertained by calculation.' p. 246.

XII. A new Eudiometer, accompanied with Experiments, elucidating its Application. By William Hasledine Pepys, Esq. Read June 4, 1807.

The principal advantage of this ingenious contrivance, in which the re-agents intended to act on the gas to be examined are inclosed in a gum elastic or indian-rubber bottle, but which we cannot describe very intelligibly within moderate limits, is that of measuring the absorption of oxygen gas more accurately, even to the thousandth part of a cubic inch, than the apparatus in common use. With this advantage, it has also that of performing the process with completeness and accuracy; it is of easy construction, and very portable.

XIII. Observations on the Nature of the new celestial Body discovered by Dr. Olbers, and of the Comet which was expected to appear last January in its Return from the Sun. By William Herschel, LL. D. F.R.S. Read June 4. 1807.

We find nothing worth recording in that part of these observations which relates to the planet, or, as Dr. Herschel will still have it, the asteroid? Vesta, except, that with a power of 577 the diameter of the visible disc of the asteroid' is about a 9th or 10th part of that of the Georgian planet.

The remaining part of this paper respects what Dr. Herschel, by a singular phraseology, terms the expected comet.' It was seen both by the doctor's sister Carolina, and himself: the following is the conclusion of the memoir.

• When I compare these observations with my former ones of 15 other telescopic comets, I find that out of the 16 which I have examined, 14 have been without any visible solid body in their centre, and that the other two had a very ill defined small central light, which might perhaps be called a nucleus, but did not deserve the name of a disk.' p. 266.

We wish the Doctor, instead of presenting the public with his crude speculations on coloured rings, had ascertained and described the principal elements of these comets: such an undertaking would fall more within his province,