Mr. Sibson first examines the Movements of Respiration in Health, and commences by dividing the ribs into three sets, terming the first to the fifth inclusive, thoracic,-the ninth to the twelfth, diaphragmatic,-and the remaining three, viz. the sixth, seventh, and eighth, intermediate.

Each of the thoracic set, he tells us, ascends during inspiration more than that next above it; consequently they move nearer to each other; while the diaphragmatic and intermediate ribs move further apart.

The following is his Summary of the Respiratory Movements in Health, which we extract at length:

"In the healthy robust male, the movement of the sternum and of the thoracic and intermediate ribs, from the first to the seventh, is from 02 to 07 inches, during an ordinary inspiration, and from 5 or 7 to 2 inches (the amount varying with the extreme breathing capacity) during a deep inspiration. The ordinary abdominal movement (diaphragmatic) is from 25 to 3 inches, the extreme 6 to 16 inches. The ordinary lateral expansion of the diaphragmatic or lower ribs is greater, and the extreme expansion is usually less, than the respective ordinary and extreme expansion of the thoracic or upper ribs. The expansion of the second ribs is usually alike on both sides; below, all the inspiratory movements, especially those over the heart, are usually somewhat less on the left side than on the right, both during ordinary and extreme inspiration.

"In the healthy boy, owing to the greater flexibility of the costal cartilages, the extreme movement of the thoracic ribs is greater in proportion to the breathingcapacity than it is in the adult; the upper part of the sternum advances more than the lower end during a deep inspiration; but there is little decided difference during tranquil respiration.

'In the old man, owing to the consolidation of the cartilages, the motion of the sternum during respiration is usually greater than that of the ribs (in the youth it is less), and the lower end of the sternum usually advances more than the upper. "In females, the thoracic expansion is exaggerated, and that of the diaphragm and of the lower ribs is restrained, owing in great part to the use of tight stays. The difference is much greater when the stays are on than when they are off.

"When the stays are on, the thoracic movement at the second rib is from '06 to 2 inches; the abdominal from 06 to 11 inches. When they are off, the thoracic movement is from '03 to 1 inches, and the abdominal from 08 to 2 inches.

"The restrained movement of the lower ribs, during a deep inspiration, is much greater when the stays are on, than when they are off.

"In infants, the thoracic expansion is considerable, being from '02 to 12 inches; while the abdominal is from 06 to 15 inches. The lower end of the sternum and the adjoining ribs, usually recede during inspiration, especially if the abdomen be large and the inspiration quick or sobbing." (pp. 376-7.)

Regarding the Rhythm of Respiration, it is remarked, that, in the perfectly tranquil breathing of adults, the inspiration is equal to the expiration; while, under excitement and change of age, the latter becomes prolonged, as compared with the former.

Having treated of the modifications of respiration during health, Mr. Sibson proceeds next to explain the Causes that disturb the Respiratory Movements, the Lungs themselves being healthy.

The motions of the ribs on both sides are restrained in posterior curvatures of the spine; those on one side in lateral curvature of the spine, injury or disease of the ribs, of the intercostal muscles, including pleurodynia, of the mamma; or of the axilla, shoulder, or arm; and probably in hemiplegia.

The motion of the diaphragm is restrained throughout by peritonitis, abdominal tumours, especially those connected with the diaphragm, and

aortic aneurism. It is restrained on the right side only by greatly enlarged liver, from abscesses or hydatid cysts, and adherent liver. Shortened expiration may be regarded as one of the effects and signs of peritonitis.

Cases of general abdominal distension from flatus, ascites, or extensive, enlarged, and adherent ovarian cysts, are those in which the action of the diaphragm is slightly lessened during ordinary inspiration, considerably restrained during a deep inspiration.

We are told that ovarian cysts of moderate size, free from adhesions, and the impregnated state, even to the last months, do not affect the respiratory movements either during tranquil or deep inspiration.

None of the above causes of altered respiratory movements, except peritonitis, affect the rhythm of respiration; and this negative circumstance is one of the means by which they may be distinguished from diseases of the organs of respiration.

The third head of inquiry is, the Effect of Diseases of the Respiratory Organs on the Movements of Respiration.

The first section of this part of the subject treats of the effects of obstruction in the outer breathing-passage on the movements of respiration; which effects are principally visible in the sinking-in of parts of the thoracic parietes, which, in ordinary inspiration, are either raised or remain fixed in their position. Thus, when the obstruction to the entrance of air is slight, as in an instance of enlarged tonsils, only the lower end of the sternum falls in. If the obstruction be a little greater, the sixth costal cartilages in addition fall in. If it be still greater, as in a case of laceration of the larynx and trachea, the upper end of the sternum in addition falls in. If still greater, as sometimes from bronchocele, the fourth costal cartilages in addition fall in. If still greater, the second costal cartilages in addition fall in.

While, in extreme cases, all the thoracic and the intermediate ribs may collapse during inspiration, in every case, the lower or diaphragmatic ribs move outwards to the normal or to an exaggerated extent. In similar cases, the expiratory movements are just the reverse of inspiratory; that is to say, when a rib falls back in inspiration, it advances in expiration. In all cases of obstruction to respiration from laryngitis, expiration is longer than inspiration; it is so generally in obstructions at the commencement of the air-passages.

In emphysema and bronchitis we witness the effects of obstruction in the smaller bronchial tubes. In emphysema, and to a less extent in bronchitis, the form of the chest and abdomen and the position of the viscera are the same that they are during the deepest possible healthy inspiration. The chest is full and prominent, the shoulders raised, the spine curved, the sternum forward, the costal cartilages at each side of it full, but not so prominent as usual. The diameter of the chest is everywhere increased; the abdomen, just below the xyphoid cartilage, is unusually hollow, the lower boundaries of the lungs and heart are a full inch lower than in the normal state.

In inspiration, the diaphragm descends, the abdomen protrudes, and the first, second, third, and fourth ribs ascend and advance with energy at the same time; the lower end of the sternum and the sixth cartilages fall backwards in the greater number of cases from childhood to the age of fifty. The intercostal spaces fall in during inspiration.

In old age, and in adults with stiff and ossified cartilages, the lower end of the sternum advances, and the ribs move outwards.

As both the superior thoracic and the diaphragmatic muscular actions are always, and the movements usually, exaggerated, the head is lowest at each inspiration, indicating excess of costal (query, spinal?) motion; while the larynx descends considerably, indicating excess of diaphragmatic action.

The rhythm of respiration is materially and characteristically affected in Emphysema and Bronchitis. The inspiration is short; the expiration is prolonged. During expiration the air rushes out easily and quickly at first, but with increasing slowness and difficulty towards the end; and this increasing slowness of expiration distinguishes obstruction of the smaller bronchi from obstruction in the larynx, in which latter case it is also prolonged, but is equally slow throughout.

Pleuritis usually restrains the respiratory movements, sometimes because of pain, but sometimes although there be no pain. In some cases the movements are not at all lessened, and, in simple or dry pleuritis, they are seldom, if ever, entirely destroyed. The respiratory movements of the opposite lung and of the unaffected portions of the same lung, are from compensation exaggerated.

We pass on to make some extracts from the summary of the effects of phthisis on the movements of respiration:

"There is almost invariably some movement of inspiration over a cavity. But although the part in question always advances during inspiration, especially a deep inspiration, yet at the beginning of inspiration it sometimes recedes slightly, and frequently stands still just before its inspiratory advance.

"The firm walls surrounding a cavity have no inspiratory expansion; the respiratory movements over the region of dullness surrounding a cavity are much smaller than those over the cavity itself; they are often immobile; their motion is often reversed at the beginning or through the whole course of inspiration and expiration.

"The descent of the diaphragm is somewhat restrained on the affected side in about one half the cases. If the diaphragm act freely, the movements of the sixth costal cartilage may be reversed. The respiratory movement of the opposite lung is, in the great majority of cases, exaggerated." (pp. 455-6).

In the fourth part, the Effects of Diseases of the Heart and Pericardium on the Movements of Respiration are considered.

In severe cases of pericarditis with effusion, in which the central border of the diaphragm is inflamed, the motion of the abdomen at the centre may be diminished, absent, or reversed during inspiration, and the movements of the left fourth, fifth, and sixth cartilages may be reversed (either wholly, or only at first), abolished, or diminished.

When the heart is materially enlarged, the expansion of the lower end of the sternum and of the cartilages and ribs in front, and to the side of the cardiac region, is restrained.

If there be pericardial adhesions, with valvular disease and enlargement of the heart, the costal expansion in front of the heart is restrained. Moreover, while the movements of the centre of the chest and abdomen are restrained, the lateral superior movements of the former, and the lateral movements of the latter, are not restrained; the extent of the impulse, too, is not lessened during inspiration.

The author has given, near the end of his paper, a list of the several modifications which respiration may undergo, arranging, under each variety

of deviation from the healthy movements, the diseases which give rise to that particular abnormal condition. He admits that we cannot form a diagnosis of disease, by observing the arrest, restraint, or exaggeration of any particular respiratory movement; but contends that we may thereby make a good step towards it, inasmuch as we narrow our inquiry to a certain small class, and make out the seat of the disease by our inquiry. Extensive tables are appended, in which are recorded the results of two hundred different cases observed in health, or under various diseases, on which are founded the conclusions set forth in the paper.

It will be manifest from the copious abridgment we have made, that many of the facts detailed are not new to medical men; still we conceive that, even with regard to these, Mr. Sibson's researches have given increased certainty and precision to our knowledge; while he has pointed out some cases of disease, which his method of measurement is calculated to elucidate, and to which it had not previously been generally applied.

The care and industry with which his memoir has been prepared, reflect great credit upon its author; and we must ever rank among the benefactors of the art of medicine one who has done so much to facilitate the practical diagnosis of disease.

ART. III.

1. KOSMOS. Entwurf einer physischen Weltbeschreibung. Von ALEXANDER VON HUMBOLDT.-Stuttgard u. Tubingen. 8vo. Erster Band, 1845, pp. 510; Zweiter Band, 1847, pp. 544.

2. COSMOS. A Sketch of a Physical Description of the Universe. By ALEXANDER VON HUMBOldt. Translated from the German by E. C. OTTE.-London, 1848-9. In Two Volumes, post 8vo, pp. 826.

3. Briefe über Alexander von Humboldt's Kosmos. Ein Commentar zu diesem Werke für gebildete Laien. Erster Theil. Bearbeitet von BERNARD COTTA, Professor.-Leipzig, 1848. 8vo, pp. 366.

Letters on the Cosmos. Being a Popular Commentary on that Work. By Professor COTTA. First Part.

4. Kosmos für Schulen und Laien nach Alexander von Humboldt. Von Dr. K. G. REUSCHLE, Professor der Mathematik und Geographie zu Stuttgart.- Stuttgart, 1848. 8vo. Erster Theil, pp. 212; Zweiter Theil, pp. 304.

Cosmos for Schools and General Readers. By Professor REUSCHLE.

No one can rise from the perusal of the COSMOs without the conviction that he has read a most extraordinary work-a work equally remarkable for the profundity of its knowledge in the most varied departments of science, its rich stores of literary research, and the captivating style in which it is written.

The Cosmos, when completed, will form three volumes, of which two only are yet published; and we fear that the advanced age and recent indisposition of its illustrious author render it far from certain when the third volume will appear, or whether it will appear at all. The first volume comprises a sketch of all that is at present known regarding the

physical phenomena of the universe; the second is divisible into two distinct and separate parts, the first of which treats of the incitements to the study of Nature afforded by descriptive poetry, landscape painting, and the cultivation of exotic plants; while the second and larger part enters into the consideration of the different epochs in the progress of discovery and of the corresponding stages of advance in human civilization. The third and last portion of the work "will, for the better elucidation of the general picture of nature, set forth those results of observation on which the present condition of scientific opinions is principally based," and will thus, probably, fill up several apparent blanks in the volumes already published.

Alexander von Humboldt was born on the 14th of September, 1769; and is therefore now in his 80th year. None of our readers can be altogether ignorant of his extensive researches in the physical geography of the New World, carried on between the years 1799 and 1804, or of the results of his scientific journey to Siberia in the year 1828, in company with his distinguished friends, Ehrenberg and Gustav Rose, and under the special protection of the Russian government. We merely allude to these points because he refers to them in his preface, in which he beautifully and feelingly explains the reasons that have induced him to undertake the present work, and sets forth, with truth and simplicity, his peculiar qualifications for such a task. "In the late evening of an active life, I offer to the public a work, whose undefined image has floated before my mind for almost half a century. I have frequently looked upon its completion as impracticable, but as often as I have been disposed to relinquish the undertaking, I have again-although, perhaps, imprudently-resumed the task." The idea of a physical description of the universe, such as he had conceived and resolved to work out, does indeed present startling difficulties; but if any man be qualified to meet and successfully grapple with those difficulties, Alexander von Humboldt is that man.

"Although the outward relations of life, and an irresistible impulse towards knowledge of various kinds, have led me to occupy myself for many years-and apparently exclusively-with separate branches of science, as, for instance, with descriptive botany, geognosy, chemistry, astronomical determinations of position, and terrestrial magnetism, in order that I might the better prepare myself for the extensive travels in which I was desirous of engaging, the actual object of my studies has nevertheless been of a higher character. The principal impulse by which I was directed, was the earnest endeavour to comprehend the phenomena of physical objects in their general connexion, and to represent nature as one great whole, moved and animated by internal forces. My intercourse with highly-gifted men early led me to discover that, without an earnest striving to attain to a knowledge of special branches of study, all attempts to give a grand and general view of the universe would be nothing more than a vain illusion. These special departments in the great domain of natural science are, moreover, capable of being reciprocally fructified by means of the appropriative forces by which they are endowed. Descriptive botany, no longer confined to the narrow circle of the determination of genera and species, leads the observer who traverses distant lands and lofty mountains to the study of the geographical distribution of plants over the earth's surface, according to distance from the equator and vertical elevation above the sea. It is further necessary to investigate the laws which regulate the differences of temperature and climate, and the meteorological processes of the atmosphere, before we can hope to explain the involved causes of vegetable distribution; and it is thus that the observer who earnestly pursues the path of