Imatges de pàgina
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Of the terms here propofed, it may be observed, that fome of them are doubtlefs more fignificant and appropriate than thofe hitherto employed; while, on the other hand, others of them appear to have little or no advantage over thofe formerly in ufe. Againft this new Nomenclature it may alfo be objected, that not unfrequently it prefents definitions in place of appellations; thus, that part of the medulla fpinalis, which is generally known by the name of cauda equina, is here called the bundle of the lumbar and facral nerves.

The fubjects which form the contents of this work, are difcuffed in the following order: 1. Anatomy, in which part the author follows Cuvier and Dumeril. 2. History of Difeafes. 3. The Vital Functions. The hiftory of diseases fhould, we think, have been confidered laft; it being certainly improper to introduce the medical ftudent to an acquaintance with the morbid derangements of the human body, before he has acquired a knowledge of the actions or functions of the various organs and other parts of the system, in a ftate of health. The general claffification of diseases is, in feveral refpects, liable to objection, as well as the particular divifions and diftinétions of fevers; but the hiftories of the diseases themselves are drawn up with neatness and accuracy. We cannot beflow the fame praise on the curative obfervations, which are by much too general, and exhibit a marked conformity with the doctrine of Brown; the novelty and illufive fimplicity of whofe fyftem, it would appear, have pro

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cured admirers and profelytes in France, as well as in Germany and Italy.

When, however, we confider this work in its whole extent, we must allow that it embraces fubjects of great importance, and that these fubjects are, in general, expounded with much perfpicuity. The anatomical defcriptions and phyfiological obfervations, conftitute by far the most valuable portion of thefe volumes; and although fuch obfervations are, for the most part, derived from others, yet this author is entitled to the merit of bringing them under one point of view, and of difpofing and combining them, fo as to render them more generally intelligible and useful.

As a fpecimen of the author's manner of writing, we fhall extract from the fecond volume, his reflections on the General Difpofition of the Anatomical Structure.

"The structure of the different fyftems of organs in man is not effentially different from the ftructure of thofe of animals, and especially of those which compose the clafs of the mammalia.

"The bones, the mufcles, the veffels, the nerves, the organs of fecretion, and those of the different fenfes, feem to be exactly the fame, a few differences in regard to form, fize, and pofition excepted.

"All these organs, in the last result, feem to be merely a tiffue of veffels and nerves differently arranged, in the interftices of which are depofited albuminous, gelatinous, adipofe, faline, &c. substances, which give them folidity, and form the parenchyma.

"Thefe different tiffues, though their intimate ftructure be unknown, form feveral anatomical fyftems of organs, which ought to be carefully diftinguished, because they exhibit analogous functions and diseases.

"Thefe different anatomical fyftems of organs are in particular; the bones, the mufcles, the veffels, the nerves, the fibrous, the mucous, and the ferous membranes, the glandular organs, the cellular tiffue, and the skin,

"The bones are formed of a tiffue of veffels, in which are fecreted and depofired the phosphate and carbonate of lime, that give them folidity. The life of the bones is maintained by the circulation eftablished between the veffels of the periosteum, those of the bodies of the bones, and thofe of the medullary tiffue.

"The mufcles are compofed of bundles of fibres; each fibre feems to be formed of several other smaller fibres, feparated and enveloped by cellular tiffue; and this fubdivifion of the fibres into fmaller ones, alfo feparated and enveloped by cellular tiffue, is indefinitely continued. The arrangement of the mufcles in long contractile fibres renders them very proper for performing great motions.

"The arteries, compofed of a thick and compact tiffue, diftribute the blood to every part of the body. They are divided and fubdivided indefinitely; and our eyes, aided by the best inftruments, are incapable of following them fo far as to be able to discover in what manner they terminate in the different organs,

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"The veins and the lymphatic veffels are of a loofer tiffee, and their fides are not fo thick. It is as difficult to difcover the origin of thefe veffels as to obferve the termination of the arteries.

"The nerves are whitifh cords formed of fibres in bundles: each fibre is composed of a foft pulpy part, enveloped by a membranous fheath. The foft and pulpy part of the nerve arifes immediately from the substance of the cerebrum, of which it feems to be a continuation: it is covered from its origin with the membranous sheath or vagina, and never quits it but at the termination of the nerve in the organ where it expands.

The fibrous membranes of a white and compact tiffue form a covering around the bones: they compofe the ligaments and articular capfules, the tendinous and the aponeurotic part of the muscles, and are obferved alfo around fome other parts.

"The mucous membranes are those which line the pneumo-gaftric and the genito-urinary paffages; the furface of them is covered with glandulous follicles, which give it a velvety appearance. These membranes fecrete a humour always vifcid; the nature of which, however, is different in the different parts.

"The ferous membranes compofe the exterior part of most of the organs, the interior part of which confifts of mucous membranes; and, in general, they cover all the furfaces of parts which are only contiguous and fubject to reciprocal friction; fuch as the infide of the articular capfules, of the tendinous vaginæ, of the pleura, &c. They continually fecrete a ferous matter, by which these surfaces are lubricated.

"The glandular organs comprehend, 1ft, the lymphatic glands deftined for affimilating the ferous liquids before they are mixed with the blood; zd, the vifcera fet apart for fome particular fecretions, fuch as the kidneys, the liver, &c. The organic ftructure of these various parts is different.

"The cellular tiffue, of a loofe nature, is diftributed around all the organs, and ferves to unite them; it fecretes and retains in its areola that adipofe fubftance which conftitutes fatnefs.

"The fkin is compofed of a vafcular, thick, and whitish fubftance, which forms the dermis, or fkin, properly fo called: it is lined by the mucous body which gives the skin its colour, and the whole is covered by imbricated lamine, dry, and in fome measure inorganized, which form the epidermis. The fkin contains alfo in its fubftance fmall glands and the bulbs of the hair.

"All these fyftems of organs difcharge their particular functions by the influence of the nerves which are diftributed to them. The nerves they receive may come from the encephalon, the vertebral prolongation, or from the ganglions of the tri-fplanchnic, and thus give them different modes of fenfibility.

"The fystems of the functions exhibit phænomena varied in proportion to the greater or lefs number of the anatomical fyftems of or gans which enter into their compofition, and which each carry thi ther, as we may fay, a particular kind of life. Thus, in the fyftem of vifion, when the action of the optic nerve ceafes, the eye no longer perceives the impreffion of the rays of light, yet it continues to live

and

and to move: if the muscles of that organ become palfied, the eye neither fees, nor is capable of motion. In the laft place, if the action of the nerves of its vafcular tiffue is gradually diminished, the organ is abandoned to the laws of affinity, and falls into a fate of pu trefaction.

"It muft here be obferved, that independently of the compound action of the different fyftems, there are effected, in every point of the organization, a continual fecretion and abforption, for which the nerves convey the principle of action, and the arteries the materials of nutrition." P. 72.

We shall here dismiss a work which will be found of utility to medical students, by giving a new and convenient form to the facts of Comparative Anatomy.

ART. XI. A Treatife on Painting, by Leonardo da Vinci. Faithfully tranflated from the Original Italian, and now first digefted under proper Heads, by John Francis Rigaud, Elg. Academician of the Royal Academy of Painting at London, and alfo of the Academia Clementina at Bologna, and the Royal Academy at Stockholm. Illuftrated with Twenty-three Copper-Plates, and other Figures. Ta which is added, a new Life of the Author, drawn up from authentic Materials till now inacceffible. By John Sidney Hawkins, Efq. F. A. S. 8vo. 311 pp. 9s. 6d. Taylor, High Holborn. 1802.

ON

N the fame of Leonardo da Vinci, his fuperior skill in anatomy, and the characteristic merits of this Treatife on Painting, feveral times publifhed before in our own language, it is fuperfluous to expatiate. Mr. Rigaud, who undertook the care of the prefent edition, promises the reader a more clofe attention to the original, and an efpecial regard to perfpicuity and precifion. He has taken alfo a new frep, which may best be explained in his own words.

"Nor was this the only advantage which it was found the prefent opportunity would afford; for the original work confitting in tact of a number of entries made at different times, without any regard to their fubjects, or attention to method, might rather in that state be confidered as a chaos of intelligence, than a well-digested treatise. It has now, therefore, for the firft time, been attempted to place each chapter under the proper head or branch of the art to which it belongs; and by fo doing, to bring together thofe which (though related and nearly connected in fubftance) flood, according to the original arrangement, at fuch a diftance from each other as to make it trouble

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fome to find them even by the affiftance of an index; and difficult, when found, to compare them together." P. viii.

That this plan is judicious, is evident at firft fight; and, for the execution of it, the public may fafely rely on the talents and experience of fo approved an artift as Mr. Rigaud. That the correfponding Chapters in the original may eafily be found, a table of the prefent arrangement is fubjoined, adding, under each article, the number of the correfponding Chapter in the Italian. To facilitate, on the other hand, the reference from the tranflation to the original, it would be an eafy and useful addition to infert a table of mere numbers, following the order of the old Chapters, and placing against them the numbers of the prefent edition. As the Chapters of Leonardo are perfectly detached and defultory, no objection whatever can be made to a departure from an order which was merely accidental; and it is fupplied, with great advantage, by a sci, entific arrangement under the following heads. 1. DRAWING; divided into the feƐtions of 1, Proportion; 2, Anatomy; 3, Motion and Equipoife of Figures; 4, Linear Perspective. II. 1. INVENTION OR COMPOSITION; 2, Expreffion or Character. III. 1. LIGHT AND SHADOW; 2, Contrast and Effect; 3, Reflexes. IV. COLOURS AND COLOURING; 1, Colours; 2, Colours in regard to Light and Shadow; 3, Colours in regard to back Grounds; 4, Contraft, Harmony, and Reflexes, in regard to Colours; 5, Perfpective of Colours; 6, Aerial Perfpective. v. MISCELLANEOUS OBSERVATIONS. 1, Landfcape; 2, Mifcellaneous. Nothing can be clearer than that, by being thus digefted, the remarks of this great mafter are rendered much more ufeful to the ftudent, who may always know at once to find whatever applies to his immediate purpose; and every reader may eftimate with much greater ease, in this form, the quantity of inftruction really contained in the Treatife. The public therefore is highly indebted to Mr. Rigaud, for the care he has taken in thus digefting and methodizing, a moft admirable collection of defaltory precepts. The life of Leonardo da Vinci is written without affectation, in a sensible and proper ftyle; and will be found pleafing acceflion to the book. It is followed by a lift of the author's works. From this Life we fhall felect the account of Leonardo's MSS. now extant, and the hiftory of them, as it was given by a perfon through whofe hands they passed at an early period.

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"On inquiry then we learn, that Leonardo's productions of this kind confit of fourteen manufcript volumes, large and fmall, now in the library of the National Institute at Paris, whither they have been

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