about another, inclined at any angle to the former; and also a new, and comparatively concise, demonstration of the equations of the motion of rotation of a solid body, its centre of gravity being fixed, and the body being acted on by any forces.

The Society then adjourned over Whitsun-week to meet again on the 14th June next.

June 14, 1838.

His Royal Highness the DUKE of SUSSEX, K.G., President, in the Chair.

A paper was read, entitled, "Researches on Suppuration;" by George Gulliver, Esq., Assistant Surgeon to the Royal Regiment of Horse Guards. Communicated by John Davy, M.D., F.R.S., Assistant Inspector of Army Hospitals.

The author, in consequence of some theoretical views of the suppurative process, was led to undertake an examination of the blood in the different forms of fever accompanying inflammation and suppuration; and the result has been the detection of globules of pus in that fluid in almost every instance where there had existed, during life, either suppuration, or great tumefaction of the external parts without the presence of pus. The means by which he detected pus in the blood were partly chemical, and partly by the aid of the microscope. Availing himself of the solvent power which water exerts on the globules of the blood, while it has no action on those of pus, he had merely to dilute the suspected blood sufficiently with water, by which means the red globules were made to disappear, while those of pus remained at the bottom of the fluid, and were easily recognised by a good microscope. A number of cases are detailed, from which the general result, above stated, was deduced. He considers that his experiments tend to establish the conclusion that suppuration is a kind of proximate analysis of the blood. As the fibrin separated from this fluid produces swelling of the part affected, or is attracted to the contiguous tissue for the reparation of the injury, the globules of the blood, altered by stagnation, become useless, and are discharged as excrementitious matter from the system. Such is the constitution of healthy pus: but when mixed with broken down fibrin, it assumes the flaky and curdled appearance, with proneness to putrefaction, characterising unhealthy pus, and the presence of which in the blood is connected with fevers of the inflammatory or typhoid form.

A paper was also in part read, entitled, "Researches on the Tides," Ninth Series; by the Rev. W. Whewell, M.A., F.R.S.,

&c.

FRANCIS BAILY, Esq., V.P. and Treas., in the Chair.

The Treasurer announced from the Chair that a deputation of the Society, consisting of His Royal Highness the President, the VicePresidents, Treasurer, Secretaries, and other Members of the Council, waited yesterday on Her Majesty, for the purpose of receiving Her Majesty's signature in the Charter-book of the Society, as Patroness of the Royal Society, when Her Majesty was graciously pleased to inscribe her name accordingly; on which occasion His Royal Highness made the following address:

"MAY IT PLEASE YOUR MAJESTY,

"IN obedience to your gracious Commands, the President and the Council of the Royal Society for the promotion of Natural Knowledge now appear in your Royal presence, humbly to tender the register of its Members for the insertion of your august signature.

"Our very name and the recollection of our first institution prompt and encourage us to look up to Your Majesty as our Patron and Protector; and which, by this especial act of your favour, will confirm to the Society the assurance so graciously communicated to us, in your name, by the Secretary of State for the Home Department, in reply to the dutiful Address we had the honour to present to your Majesty on your accession.

"Permit me, Most Gracious Sovereign, to avail myself of this opportunity to express to your Majesty, in the name and on the behalf of the Fellows of the Royal Society, their gratitude for your munificent grant of two Gold Medals annually, for the encouragement of Science in its different branches; and more especially for allowing the Council so to alter for the present year the statute regulating the distribution of them, as to render it available and conformable to the view for which it was framed.

Peace, Navigation and Commerce, are as necessary to the growth of Literature, as to the intercourse with the Natural World.

"Of these blessings we were already in possession when Your Majesty ascended the Throne of your Ancestors. That such may continue to exist and thrive in this happy country during a long, prosperous, and useful reign, with every other earthly

felicity which Divine Providence in its wisdom may deign to shower down on Your Royal and Sacred Head-is the most ardent wish and fervent prayer of the President, Council, and Fellows of the Royal Society, in unison with all your other loyal subjects."

The following papers were then read, viz.

"On the structure of the teeth, the vascularity of those organs, and their relation to bone." By John Tomes, Esq. Communicated by Thomas Bell, Esq., F.R.S., Professor of Zoology in King's College, London.

The microscopical examinations which the author has made of the structure of the teeth of man and various animals, lead him to the conclusion that their bony portions are formed of minute tubes, disposed in a radiated arrangement, in lines proceeding everywhere perpendicularly from the inner surface of the cavity containing the pulp. These tubuli are surrounded by a transparent material, which cements them together into a solid and dense mass. He finds, by applying the test of muriatic acid, that carbonate as well as phosphate of lime enters into their composition. In man, the tubuli, during their divergence from their origin at the surface of the central cavity, send off a number of very minute fibrils; and on approaching the enamel or the granular substance, which cover respectively the crown and the fangs of the tooth, the tubuli divide into smaller ones, which freely anastomose with one another, and then either are continued into the enamel, or terminate at the boundary between these two substances. Various modifications of this structure, exhibited in the teeth of different animals, in the class Mammalia and Fishes more particularly, are minutely described. The granular substance appears to be composed of irregularly shaped osseous granules, imbedded in the same kind of transparent medium which cements the tubuli together. External to the granular portion, the author finds another substance entering into the formation of the simple tooth, and commencing where the enamel terminates; and which he describes as beginning by a thin and transparent layer containing only a few dark fibres, which pass directly outwards; but assuming, as it proceeds towards the apex of the fang, greater thickness and opacity, and being traversed by vessels.

External to the enamel, and in close connexion with it, in compound teeth, is situated the crusta petrosa, a substance very similar to the bony layer of the simple tooth. It contains numerous corpuscles, and is traversed by numerous vessels entering it from without, and anastomosing freely with one another, but terminating in its substance. These investigations of the structure of the different component parts of teeth, furnish abundant evidence of their vascularity and consequent vitality.

"On the evolution of Nitrogen during the growth of plants, and the sources from whence they derive that element." By Robert Rigg Esq. Communicated by the Rev. J. B. Reade, M.A., F.R.S., &c.

In this communication the author follows up his inquiry into the

influence and importance of nitrogen in vegetable physiology, by noticing, in the first place, the experiments of Dr. Daubeny, M. De Saussure, Sir Humphry Davy, and those which he himself has made ; all of which tend to prove that nitrogen is evolved during the healthy performance of the functions of plants; that the proportion which it bears to the oxygen given off is influenced by the sun's rays; but that owing to the necessary exclusion of the external atmosphere during the progress of the experiments, it is impossible, with any degree of accuracy, to calculate the volume of these evolved gases during any period of the growth of plants in their natural state.

If to this indefinite quantity of nitrogen given off by plants there be added that definite volume incorporated into their substance and shown in the author's former tables, the question arises, whence do plants derive their nitrogen, and does any part of it proceed from the atmosphere? A problem which the author proposes to solve by a series of tabulated experiments upon seeds, and seedling plants, indicating a large excess of nitrogen in the latter, and under such circumstances of growth that he is compelled to fix upon the atmosphere as its source.

By the same mode of experimenting, the author attempts to show that the differences which we find in the germination of seeds and the growth of plants in the shade and sunshine, are apparently due in a great measure to the influence of nitrogen. And he concludes by observing, that he does not touch upon the practical application of the subject wherein the real value of the inquiry consists; it is his object to draw attention to an element which, though in some instances so minute in quantity as to be with difficulty detected in our balances, has nevertheless been wisely assigned to discharge the most important functions.

Com

On the decussation of fibres at the junction of the Medulla Spinalis with the Medulla Oblongata." By John Hilton, Esq. municated by P. M. Roget, M.D., Sec. R.S.

The author first alludes to what usually happens in affections of the brain, namely, that the loss of voluntary power and of sensation manifest themselves in the opposite side of the body to that in which the cerebral lesion exists, a fact which has been attempted to be explained by the crossing of the fibres at the junction of the medulla oblongata with the anterior or motor columns of the medulla spinalis; but such a structure, he observes, affords no explanation of the loss of sensation. The author then, referring to the communication of Sir Charles Bell to the Royal Society, in the year 1835, describing a decussation connected with the posterior columns, or columns of sensation, mentions that the accuracy of these dissections was doubted by Mr. Mayo and other eminent anatomists. The author proceeds to state that the symptoms of cerebral lesion do not always take place on the opposite side of the body to that in which the lesion of the brain exists, but that they occur sometimes on the same side; that the loss of power and of sensation, although confined to the same side, may exist in either the upper or the lower extremity;