rished in the reign of Adrian; and it is well known that Theodosius compiled his code in the year 435 of the Christian ærà,

We now proceed to vol. IV. of Physical and Mathematical Sciences-a volume which will not rank very high among the scientific publications of the learned societies; and, as we have already had occasion to remark, we regret the loss of many distinguished authors. We think, however, that, on the whole, the work improves: but much further improvement is wanting, before the Institute' can rival the Academy.'

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The first subject, as usual, is the prizes: the proposal, in the former volume, has obtained no success, though the inqui ry was a valuable one; viz. An anatomical Comparison of the Liver in different Animals. It is now, therefore, superseded by another; viz. The Cause and the Appearances of the Torpor of Animals during Winter.' A list of the memoirs which merit publication among the labours of learned foreigners, is next added; and it is followed by the machines, inventions, &c. approved by the class, and a catalogue of the works presented to it in the years 7 and 8. An observation, communicated by C. Aurejac, we must add in the original tongue.

Une petite fille de quatre ans, qui depuis dix mois éprouve périodiquement l'écoulement menstruel, comme l'éprouveroit une fille arrivée à l'age de puberté, tant pour la quantité que pour la qualité.'

The lives styled 'Notices historiques' are those of MM. Heritier, Gilbert, and Darcet, by M. Cuvier; and of J. C. Borda, by M. Lefevre Gineau. On these we cannot enlarge.

The first memoir is entitled, Monography of the Genus Tilia, the Linden Tree.'-Linnæus was acquainted only with the European and American tilia: Miller divided the latter into two species-the American, described by Linnæus, and the Carolinian, described by Catesby. The author of this memoir, M. Ventenat, the able editor of Jussieu's Systéme Végétale, has extended our views, and given a very clear and particular ac count of the different species of tilia, illustrated with plates. The tilia Europaea, with naked petals, is divided into two species-the T.microphylla,' and T. Platyphyllos.' They certainly resemble each other greatly; yet perhaps merit the distinction they have received by the separation. The tiliæ of America are the T. glabra, Americana L, the T. pubescens Caroliniana of Miller, and the T. rotundifolia, the alba of Aiton. This last species is newer, and very particularly described. A judicious account of the appearance, and the uses to which the linden-tree is applied, are subjoined.

*The word monography' is not common in English. The author, whose atten ion is confined to one genus, is termed a monographist;' and his work is of course-styled Monography.' Among botanists, the term is generally understood.

II. An Enquiry into the Integration of partial differential Equations, and of the Vibration of Surfaces, by M. Biot.'-This memoir is very extensive and recondite: it admits not of analysis: but the object of the second part, the vibration of surfaces, may require explanation. It relates to sounds like those of a drum; and our author confirms the doctrine of Euler, who considers the drum as composed of strings crossing each other at right angles. Having ascertained the nature of their vibra tions, he lessens the distance indefinitely, to attain the end proposed. This, however, is but a partial view of the question; and the vibration of musical glasses, and of the trumpet, will require a more varied and extensive research, which neither Euler nor the present author has sufficiently engaged in.

III. Memoir on the Analysis of human urinary Calculi, and on the different Substances of which they are composed, by MM. Fourcroy and Vauquelin.'-We have often had occasion to notice the subject, and in part the contents, of the memoir before us, but in the more concise form of an abstract. It was, till of late, supposed, even by the best chemists, that urinary calculi consisted only of phosphat of lime, and of uric acid; perhaps also of animal matter. To these ingredients the acuteness of the present authors soon enabled them to add an ammoniaco-magnesian phosphat, which forms a large part of the bulk of the enormous calculi, which scarcely admit of being extracted. This salt is sometimes unadulterated; sometimes mixed with either or both of the other ingredients. The mul berry-form calculi also afforded a singular ingredient, whose existence in human urinary calculi had been denied; viz. lime, generally combined with the oxalic acid; and this, with animal matter, appeared to form their chief substance. The source of this acid leads our authors to some inquiries, whether it may be taken in with the food, or be generated in the system. If it exist in the urine, it will decompose the phosphat of lime, and form a more solid calculus. It appears, however, exclusively in the bladder; for the renal calculi consist always of uric acid; and it would merit an inquiry, whether the uric may not be a peculiar form of the oxalic.

In the seventy-fourth calculus, which our authors analysed, they found another unsuspected substance; viz. a very fine flinty earth, coloured with animal matter, and mixed with some particles of phosphat of lime. The flint was found of a yellow grey or a yellow brown colour, covering a moriform nucleus, and surmounted with laminæ of the usual nature.-The animal matter, in the writer's opinion, is a peculiar substance, but can by no means be considered as the cement, since its quantity is too inconsiderable, and the crystalline form of the ammoniaco-magnesian phosphat is what it would assume without the animal matter. Our author's observations on the latter substance, in other calculi, we shall transcribe.

Our opinion of the existence of the animal matter in the mulberry-form calculi is different. Our experiments are not yet sufficiently advanced; but we have already found that it is by no means the same as in those calculi which consist of the earthy phosphats. It is in a larger proportion, constituting about one seventh of the whole; is not, as in the latter, analogous to albumen or jelly, but approaches rather to a peculiar animal extract hitherto little known, but which we have discovered in the urine, as we shall soon show. The animal matter of the mulberry calculi is brown, flocculent, granulated, deliquescent, affording the smell of garlick when burning. We have already discovered that this highly animalised substance contributes to give a form to the solid eburnean (ivory-like) consistence of the moriform calculi, since, on solution in weak muriatic acid, its fragments leave in the fluid a soft brownish substance, preserving the original figure, though so soft as to yield to the pressure of the fingers.'

Water is often a copious ingredient in common calculi, amounting to a third of the weight. The memoir concludes by reflexions the most consoling and best founded, viz. that the nature of all these concretions is such as to admit of their solution by substances which may be injected into the bladder without injury; and M. Fourcroy adds such remarks as will lead to the most probable conjecture respecting the nature of the calculus, and, of course, the choice of the injection. These remarks, however, can only be read with advantage in the me moir itself.

We must step forward to the continuation of this subject in the latter part of the volume, where we find two memoirs on the chemical and medical History of the human Urine, containing some new Facts respecting its Analysis and spontaneous Change,' by the same authors.

In the first of these memoirs, M. Fourcroy is, as usual, diffuse and wordy; yet his remarks are valuable and important. The paper contains an account of the human urine, and its constituent parts, as obtained by spontaneous decomposition, and explains the successive evolution of the different substances. The proportion of ammonia continues to increase without li mits; the uncombined phosphoric acid is saturated with it; and the proportion of ammoniacal phosphat augments, with which the phosphat of magnesia combines, forming the triple salt before mentioned, whose crystals are prismatic. The uric acid is checked in its separate précipitation, and combined with the ammonia, which is precipitated with the earthy phosphats. The acetous and benzoic acids find the same alkali, so that they never appear separate. The muriat of soda, in the urine, unites with the colouring matter, so that this decomposition

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may be checked by previously saturating the urine with this salt its crystals are octoëdral, and those of the muriat of ammonia, cubic. The carbonat of ammonia is produced so rapidly, that putrid urine effervesces with acids, and gives out this salt on the slightest heat-a property which makes it so useful to various manufacturers.

There are, however, some circumstances where the spontaneous changes of the urine do not present the same or all the appearances that we have described. Frequently, in the same person, and in a state of health nearly uniform, but undoubtedly with a change of functions not yet properly ascertained, the urine, instead of being covered with a healthy pellicle, and exhaling a violent ammoniacal smell, is, in about five or six days, overspread with a mouldiness, after depositing the red crystals of the uric acid, and a whitish cloud. The green and white mould vegetates, and increases for twenty days. Under the pellicle which it covers, and by the side where it touches the urine, we find a quantity of white prismatic crystals of ammoniacal phosphat of magnesia. The fluid does not contain any uncombined carbonat of ammonia; but, on the contrary, we find some traces of acid: it admits of the separation of a precipitate, on adding fixed alkalis during its evaporation, and exhales nearly the same odour as fresh urine. When inspissated, the muriatic acid discovers the benzoic acid, and gives an acetous smell. The nitrous acid produces white pearl-coloured crystals, like unchanged fresh urine.'

This property, of strongly alkalising in one case, and with difficulty in another, depends undoubtedly on a different proportion of the ingredients in the urine, since the latter are always the same, at least in health. We shall show that the peculiar and distinguishing matter of the urine ferments slowly and with difficulty, and requires a mucous animal substance, which must be first decomposed, as a ferment. When the urine proceeded slowly to its alkaline state, it appeared owing to a deficiency in this fermenting substance, or to its being in a smaller proportion. In this case, we do not see the mucous filaments separate, as in strongly alkalising urine.'

In the following memoir, our authors examine, with all the resources of modern chemistry, the peculiar matter which distinguishes urine from every other fluid; the soapy,' 'oily,' extractive,'' animal,' matter found in this excrementitious fluid. M. Fourcroy mistakes, when he observes that Boerhaave alone considered it as excrementitious and injurious. The same idea has been maintained by Dr. Cullen, and other modern physiologists, though probably subject to some exceptions, as we shall soon have occasion to point out. Our author's very mi

nute examination we cannot follow particularly, but shall offer the outlines as concisely as we can.

It crystallises in a flaky shining mass, composed of yellowish flakes compacted in the centre, or of particles in close union. The colour, in the deliquescent parts, is constantly brown; and it separates rapidly from urine when cold, after a hasty evaporation, or from alcohol in which it had been dissolved, and equally evaporated when cold. The smell is that of urine and garlick, insupportably fœtid, and soon producing faintness; the taste poignant and sharp; it sticks to the vessels that contain it, and becomes so hard as to be cut with difficulty. It strongly attracts water; and, when mixed with mucous matter, is highly fermentable. This fermentation is, as we have said, the source of the ammonia, the putrefaction of the urine, its peculiar smell, &c. Of 288 parts of the urée-for that is the title of this oily extractive matter in our author's memoir-the foreign matters amount to seventy-one. Of the remaining 217 parts of pure urée, 200 are changed into carbonat of ammonia, ten are separated in the form of carbonated hydrogen gas, and seven become charcoal. When reduced to elements, these 217 parts of urée really contain 85.2 of oxygen, 69.4 of azote, 32.2 of carbon, 30.2 of hydrogen. If we consider that a portion of the oxygen is employed in the formation of the water, the azote will be found the predominant principle.

From this quantity of azote, our author considers the urinary secretion as designed to separate the superabundant azote, as the lungs separate the superabundant oxygen, and the liver the superfluous hydrogen. Yet there certainly are cases in which the urinary discharge has been suspended for days and weeks, with little or no assistance from any vicarious evacuation, where even the perspiration has been scarcely or slightly urinous. On the other hand, however, the urine has been sometimes copious, without the discharge of the urée, while the most troublesome symptoms of irritation have supervened, to be removed only by the return of the peculiar smell and colour. On the whole, the author seems to rest too strongly on the separation of this matter, and to represent what is generally necessary, as indispensable. His memoirs are, in few words, highly interesting both to the pathologist and the chemist. We must now return to the others in their order.

IV. M. Portal's Description of the Intercostal Nerve in the human Body' is an admirable supplement to the labours of MM. Mechel and Walter, leaving us scarcely any thing to lament as unknown. The whole, however, is strictly anatomical; and of what our author has added to former observations, as well as some little errors which he has corrected, we cannot give a very intelligible abstract. We may add, that this is a