cavity between them. As a result, we get the pleuritic effusion which, had the hepatized lung not prevented it, would have occurred at the beginning. As the effusion increases the lung retires from the chest-wall, and eventually we have, replacing the pneumonia, a distinct pleurisy with effusion.

I should say, further, that the temperature, if it had previously declined to the normal degree, rises slightly and remains usually at 100° F. or over for a variable length of time. I cannot make a statement of any value as to the duration of this secondary fever, excepting that, in the absence of complications, it does not endure much, if any, longer than for the period of accumulation, dying away at the completion of that process.

It may be, however, as is well known to clinical observers, that the temperature will be somewhat disturbed while absorption is going on.

The pyrexia noticed during the absorption of pleuritic effusions, usually of a mild though irregular type, is probably due to the entrance of peptones into the blood.

The diagnosis of this condition which I have here described depends simply upon the observation of the foregoing facts, viz.: the occurrence of a pneumonia of, as a rule, more than the average degree of intensity, associated at its onset with the signs of acute pleurisy, which are quite variable, and the most certain of which, the friction sound, is apt to be of short duration and not followed by evidences of serous effusion; râles somewhat like a nondescript mucous râle, fine or coarse, usually both, following the friction, and frequently enduring until the beginning of resolution of the pneumonitis; closely following upon the signs of commencing resolution, a change in the percussion sound, which becomes flat; either absence or presence of the vibratory breath and voice sounds of pneumonic hepatization (vocal fremitus and bronchophony), as coincidences of the change in the percussion signs; at the same time, sinking of the intercostal grooves during inspiration, followed by bulging if the accumulation is large; return of the cyanotic appearance of the skin and mucous membranes, and increasing rapidity with diminishing vigor of the heart-beat.

Later on there may be, of course, other signs and symptoms of pleuritic effusion, such as cardiac displacement, jugular engorgement, cerebral and spinal venous hyperæmia, errors in the distribution and movements of the cerebro-spinal, subarachnoid fluid, portal congestion, and the other items of that long series of disturbances which result from the presence of large quantities of liquid in the pleural cavities, and constitute one of the most interesting chapters in pathology.

I need not occupy the space of our genial editor with a long disquisition on the treatment of the condition to which I have here attempted to call the attention of practitioners, and to elucidate as briefly as was possible.

These deviations from the classical course of wellknown and well-understood diseases must, necessarily, be dealt with in accordance with the features presented by individual cases, and as the knowledge of the physician in charge indicates to him. There is one especial point, however, that seems to require a distinct rule of practice.

When it is thought advisable to aspirate, this should be done cautiously, and the suction should be taken off the moment any depression of the intercostal spaces is seen. Otherwise the lung, which has probably not yet entirely regained its normal structure, may be injured, or the cavities of the right heart unduly dilated.

Professor Mauthner, who died on October 20th, had been Professor of Ophthalmology at the University of Vienna just one day. He succeeded the late Professor Stellwag.

SEROUS CAVITIES OR SPACES. BY BYRON ROBINSON,

CHICAGO, ILL.

SEROUS cavities or spaces are situated in various parts of the body. They have a similar function and are liable to similar diseases. The serous cavities in the order of their size are (a) the peritoneum, (b) the pleura, (c) the arachnoid, (d) the pericardium, (e) the serous cavities of the joints. Embryologic or natural development shows that serous cavities are all secondary acquisitions. We saw in the progressive growths of the embryo that the peritoneal or serous cavity arose from the mesoderm or middle germ layer. Small clefts or spaces arise in the lateral portions of the developing embryo, and these spaces finally coalesce, forming a more or less differential cavity as regards size and form.

Thus by changes in the mesoderm the peritoneal sac results. The modifications of the middle germ layer are cleavage, evagination, folding, and coalescence, which lead finally. to the structure faced with shining epithelium and backed with beds of areolar tissue the serous cavity of the abdomen. From invisible clefts in the mesoderm filled with lymph this sac increases until it comes to have about an equal surface with the skin, and will, in the adult, absorb two quarts of fluid per hour. This important membrane is finally intimately and inseparably connected anatomically and physiologically with three great apparatuses -the digestive tract, the genitals (tubes and ovaries and uterus), and the urinary organs.

This cavity is sooner or later lined by a distinct layer of flat, endothelial cells, with here and there present peculiar apertures (stomata) which are lined with what may be called germinal or glandular cells—probably absorbents leading to lymphatic tracts.

The primitive clefts or spaces in the mesoderm are filled with a fluid which resembles lymph, and to all intents and purposes the peritoneal serous cavity may be looked on as a lymphatic sac. It belongs to the lymphatic system. It is not a passive membrane, but an active absorbent, a regulator of circulation. It may be claimed that the serous membranes act as jointcavities. They give opportunity for motion. The peritoneal cavity I shall view as a joint-cavity, allowing all the movements necessary for the anatomical and physiological existence of itself and its contained functionating viscera. It may be observed that all these serous cavities, like joints, are liable to similar diseases, as inflammations, tuberculosis, etc. The serous cavities are all really closed sacs. The exception of the female in having two apertures for the Fallopian tubes is not an exception in fact, as regards the closure against the passage of serous fluid; for the valvular condition of the mouths of the Fallopian tubes does not allow serous fluids to pass from the peritoneal cavity through the uterus. Hence, practically, all serous cavities may be viewed as closed lymphatic sacs. As closed sacs they become to a certain extent regulators of pressure. This is best seen in the ventricles of the brain. The fluid sacs allow the brain or delicate organs to rest on soft water-beds, protecting them from sudden changes or trauma. The serous sacs act as buffers modifying rude mechanical movements, and distributing forces to safe regions of more resisting structures. The serous cavities with their contained fluids regulate circulation. Observe how in the horse, after vigorously running for several miles, the large dilated veins stand out on his body surface. The fluid in the serous cavities has prevented sudden changes in circulation in the vital nervous centres and the vital viscera. The fluids in the ventricles and arachnoid could not be rapidly displaced, so that the brain under the vigorous pumping of the heart is comparatively safe, for the blood is forced in directions of least resistance the wide veins and the delicate viscera are spared shock. All these

remarks apply equally well to the lymphatic joint and serous space, known as the peritoneal cavity.

These serous cavities with their contained fluids not only regulate pressure, motion, and circulation, but they are normally always full of fluids or viscera. The fluids and the viscera in the serous sacs alternately play on each other. The fluid plays a double rôle. It facilitates visceral movements with the slightest friction and fills the spaces in the sac due to small changes in the form of the viscera, thus in a certain measure distributing pressure uniformly on all contained viscera. It is in these great serous sacs that anatomy and physiology arise to their supreme significance in the animal economy. In these sacs anatomic structure and delicate visceral arrangement are combined with the most superior design of a physiologic mechanism. The serous cavities are the real physiologic laboratories of life. The anatomic limitation of serous sacs is purely for physiologic purposes. Anatomy and physiology here as elsewhere go hand in hand.

All organs are outside of serous cavities, since they are closed sacs. All viscera lie outside of the peritoneal sac. However, all viscera which have become invaginated into the walls of the serous sacs have certain supports for anatomical limitations and physiological purposes. We will not discuss here whether the supports (mesenteries, ligaments, and omenta) arise as primitive projections of the mesoderm-designed ridges of cellular tissue covered by serous epithelium-for the purpose of transmitting nerves and vessels to the enclosed viscus, or whether the supports are simply duplicatures of peritoneum. As the viscera increase in size in the adult, with the exception of the liver, they project and invaginate further and further into the cavity. The serous membrane gradually wraps itself around the viscus until it is evaginated into the sac, while its pedicle elongates. All supports (ligaments, omenta, and mesenteries) of viscera in the peritoneal cavity are the same. They consist of a double layer of peritoneal membrane. These visceral supports are not merely to anchor the organs to the wall of the abdominal cavity, but they convey vessels and nerves for the demand and supply of the organs. They are neurovascular pedicles. Fixation belongs to few abdominal organs. The liberal lengths given to the supports of viscera permit them to perform their rhythmical functions. Every viscus seems to me to have its rhythm. Rhythmical organs require space for their delicate motion, as well as for their contraction and expansion. It may be observed in the abdominal serous cavity that nerves and blood-vessels are systematically grouped, indicating an original division of the digestive tract into its three great regions-stomach, small and large bowels. The supports of the abdominal viscera vary at different times of life, and I have found by careful examinations of foetuses that scarcely any of the original mesenteric supports exist in the adult; even the mesentery of the descending colon, which I had long thought was the original mesentery, first disappears about the sixth month of fœtal life and rarely appears again, only the sigmoid mesentery represents the original. In the serous cavity of the peritoneum there are two kinds of serous membrane, which may or may not differ in structure and function. One portion of the great sac is intimately in contact with the viscera and is named visceral layer (serosa visceralis). The other portion of the peritoneum is called the parietal layer (serosa parietalis). An important factor in the peritoneum is its subserous strata. The amount of subserous tissue not only varies in thickness, but varies in localities. The peritoneal substratum on the anterior abdominal wall is very small, but the areolar tissue is abundant toward the pelvis and in the dorsal region. It is very important to be familiar with the thick beds of white, snow-like areolar tissue that underlie the serous sac. The practical application of this anatomical fact applies to hernia, the

bladder, and the uterus. It is well to observe the fact in operation on the colon and kidney, which organs can be attacked from behind. Many of the organs connected with the peritoneum are sufficiently uncovered to allow surgical procedures from behind. The excessive beds and layers of areolar tissue immediately under the peritoneum endow the peritoneal membrane with wide mobility. The membrane can move easily on its bed, it can pucker and dimple and pouch, by which process it solicits hernial projections. It is probably owing to this yielding bed of areolar tissue that visceral supports elongate (prolapse) with age. I have observed that in all fœtuses and young human subjects the visceral supports are short and the viscera are high in position, but with increasing senility the visceral supports elongate and the organs prolapse. Visceral supports are not for the purpose of preventing hernia through the contained walls, but for the purpose of allowing visceral rhythm and to prevent the organs from becoming entangled. The organs are so anchored that they seldom strangle each other by knots, twisting, or pressure. In the lower animals the digestive canal is very long and convoluted, the peritoneum is more liberal than it is in man, but the visceral supports maintain absolute order among the various organs.

A serous cavity, in general, has an important function in animal life. In viewing it as a joint we compare all movements. It comprehends also all means by which the joint maintains its existence and accomplishes its end. A smooth surface and a lubricating fluid are the essentials for motion. This peritoneal joint, or serous cavity, however, not only accommodates itself to bodily movements, but it adapts itself to functionating contents. It is a depository of changing and moving organs which subserve the object of digestion, gestation and urination, and rhythmical organs. The joint must adapt itself to viscera which have enormous changes in volume. Its walls and contents are in exquisite harmony by being supplied with branches of the same nerve-trunks.

The wisdom of having three serous cavities distinctly divided by strong partitions, though in close proximity, is apparent when one contemplates the spread of inflammatory conflagrations as well as the utility to function and physical protection by confinement. The anatomic and physiologic properties of a serous cavity and its contents present all the known perfections of the most exquisite mechanism. The slimy epithelium of the serous membrane lies on the top of deep beds of snow-white areolar tissue, which possesses properties of elasticity and yieldibility, contraction and expansion, without loss of integrity. The contained organs of the serous cavity possess mobility without dislocation. They have the power to change their form and. return to normal without losing their integrity. The organs are endowed with rhythm, elastic and muscular tissue, and varied function. The serous membrane, peritoneum, which lines the walls of the serous cavity and covers the organs evaginated into its fold, in varying degrees, not only facilitates all movements, but it regulates to a certain degree ovulation, digestion, and circulation.

serum.

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and its endothelia are flat and irregular in outline and studded here and there with stomata, whose mouths are surrounded with a ring of small cubical cells. These little mouths open into sub-adjacent lymphatic channels. The blood-vessels of the peritoneum end in a capillary net-work which especially pervades the subserous tissue. The blood vessels are much more numerous near parts of the membrane where lymphatic tissue exists.

A CASE OF LUMBAR HERNIA.

By C. M. GALLOWAY, M.D.,

XENIA, O.

W. M. R- enlisted in the Union Army on August 3, 1862, and was discharged June 9, 1865. He was a sound man physically when he enlisted. A short time after he enlisted, while on a march, his belt, which held in position his cartridge-box, cap-box, and bayonet scabbard, became twisted (because it was made of flanky leather) and caused the shank of his bayonet to rub on his left side, at the exact spot where the hernia

is now located. Soon afterward he began suffering from a severe pain in his spine, from the coccyx to the base of the brain. From that time until the date of his discharge he was able to perform light duty only. When discharged the hernia was about the size of a partridge's egg and has gradually grown to its present dimensions-five inches in length by two inches in width. About twelve years ago incontinence of urine began and is yet present, due to the presence of spinal irritation, the medical examiners say.

During the past year an abdominal hernia over the region of the stomach has made its appearance, for the relief of which he wears a truss. The man has a peculiar nervous symptom, which he states is of recent origin. When walking along the street he will unwillingly turn and walk in the opposite direction, and continue until he grasps some stationary object, and stop himself, when he can turn around and continue his walk in the original direction. At such times he feels

strange, but has no unusual pain. The lumbar tumor requires now a pad five inches in diameter to hold it in place. The patient is much emaciated and weighs one hundred and twenty pounds. The accompanying illustration shows location and size of the hernia.

THE USE OF THE BICYCLE FROM A PROFESSIONAL STANDPOINT.

BY JOHN B. RICHARDSON, M.D.,

LOUISVILLE, KY.

AFTER employing a horse and buggy, in the practice of my profession, over the streets of our city for more than twenty-two years, I found I was not getting sufficient physical exercise to prevent frequent attacks of headache and sleeplessness, and was becoming quite too corpulent for comfort. I determined to give them up and try walking. I very soon regained perfect health, but was convinced walking was too slow for long-distance visits. The use of the bicycle was the alternative, which, at that time-nearly four years ago -was considered here a great innovation, deemed, to say the least, a rather undignified or puerile species of locomotion, entirely devoid of practical utility, and its employment requiring a more than minimum degree of temerity, especially in a professional man. Possibly I was a little advanced in years to adopt such a novelty, as I had then nearly reached the shady side of the halfcentury mark. Nothing daunted, I strode my Pegasus, and found him, at first, rather unruly and difficult to manage, almost equalling" in ways that are dark" and unexpected positions and locations the proverbial mule, when first saddled and bridled.

After, however, a few four-A.M. (to escape observation and unfavorable criticisms) excursions over asphalt pavements, I mastered the wonderful steed, and now feel as much at ease on his back as when seated in my easy-chair in my study.

There are some rules by which riders should be gov erned, and in accordance with which they should act, if they wish to derive all the benefits and not fall heirs to any of the evil results of "cycling."

A perfectly fitted saddle and the proper position of the saddle stand first, being of major importance.

When seated upon the saddle, placed at the proper angle for the rider, his weight should rest upon the gluteal muscles (except what is impinging upon the pedals), and under no circumstances or at any time should any weight or pressure be permitted to fall upon the perineum, for just this and this alone (excepting falls from the machine) is the cause of most all of the cases of irritation and inflammation of the neck of the bladder, of the urethra and prostate gland, and abscesses which result from bicycle-riding. My advice to dealers in bicycles is, never allow the use of an ill-fitted saddle; do not weary of making changes in the saddles, or altering the angles at which they are placed and secured, until their proper adaptation has been perfectly accomplished, for in this lies the secret as to whether or not the use of the bicycle shall result in benefit or harm to the rider.

Where there is already existing disease of the genitourinary organs, or local irritation from any cause, the use of the bicycle is contra-indicated. Given, however, a perfectly sound person in this regard, its use within reasonable bounds will redound to his benefit and not to his injury.

The most natural, healthful, and graceful position for horseback-riding is the erect posture, with the stirrupstraps of such length as will allow the rider's legs to be almost fully extended, permitting him to bear most of his weight upon the balls of his feet on the stirrups. So, after one has learned to ride the bicycle, the saddle should be so elevated that, the rider's leg being ex

tended, the down pedal will be sufficiently low to enable him to touch it easily with the heel of his boot, thus keeping most of his weight upon his feet, and lessening the proportion of weight upon his gluteal muscles.

The rider's body being perfectly poised in the erect posture places his lungs and heart in their best possible relative position to carry on their functions, and not impede the circulation through the heart and vessels, and by pressure of contiguous parts preventing the free expansion and contraction of the air-cells, as is unavoidably done in the leaning-forward position, the latter being unnatural, ungraceful, and unphysiological, as well as invariably injurious.

A safe rule, to which there can be no exception in the use of the bicycle, and which with equal force is applicable to all other forms of exercise, is: Exercise short of fatigue. This observed, one will obviate the necessity for the obedience of a second, viz.: Rest frequently.

Excessive exercise here, as along every other line, is injurious, and is to be eschewed. With greater force does this apply to the young, growing, or physically undeveloped rider. Even in hill-climbing or rapid riding the erect posture should be assumed and maintained.

Most professional riders insist that the forward-leaning, partially-closed-" Jack-knife" position is essential to rapid riding, and many youthful riders assume it, as it smacks of the professional, to their temporary and at times permanent injury. If this be true, it cannot apply to health-seeking or pleasure-riding. Again, the assumption and retention of this position is a frequent cause of perineal troubles, bringing to bear a great amount of pressure upon those parts which should never be pressed upon, and which even the most perfectly fitted saddle cannot, in that position, be made. to prevent.

Racing, either competitive or against time, is generally injurious, unless the rider has been gradually brought to that degree of muscular development through months of careful training. Riding long distances at a rapid rate of speed can only eventuate in harm, resulting in hypertrophy of the heart and its consequent dilatation, or overstraining of other muscles or sets of muscles. Gentle exercise upon the bicycle in every healthy person, after becoming inured to its use, produces a wonderful exuberance of spirit, which if not checked will create the desire to "speed." This can be controlled if taken in the initial, but will grow upon the rider if he is not continually on the qui vive to hold it in check, and should not be indulged in by the health-seeker or the young. The subject of respiring during the use of the bicycle is one of importance. My experience in hill-climbing, or in rapid riding on the level even, is that one is forced to use mouthbreathing; but in riding on the level it is better to breathe through the nose, especially in cold weather, for it is a well-known fact that atmospherical air, after passing through the nostrils, upon reaching the air-cells of the lungs is some degrees warmer than when it passes through the mouth upon reaching the same point. Bicycle-riding causes free lung-expansion, thus dilating air-cells which during the more common forms of exercise remain quiescent, partially collapsed, and unemployed, their distention keeping them in a physiological condition causing their healthy action, and retaining them in that state in which it is most desirable to have them in both health and sickness.

Bicycling develops the general muscular system, and is not confined, as some suppose, to the muscles of the lower extremities. This will be corroborated by all wheelmen. Those of the back, chest, neck, abdomen, and also of the upper extremities are brought into constant use in the earlier essays at riding, in getting on and off, and in balancing and guiding the wheel.

of these sets of muscles are constantly employed in hill-climbing, and can be exercised by the expert rider

when he so desires, even if it be not essential on a level road.

Use but do not abuse the use of the bicycle. I am persuaded by experience and observation that ill results are generally attributable to carelessness in some one or more respects, to overuse, or to too long or too rapid jauntings; for there is no form of exercise more vivifying, exhilarating, or health-giving than excursions leisurely made, with agreeable companions, in pleasant weather, over the hills and dales of our own God-blessed “Bluegrass Country."

A very wise and observant old Friend-a laymanremarked to me many years since: "Antidote for indigestion, eat less. For nervousness, exercise in the open air and sunshine." His conclusions were axiomatic.

I have prescribed for many sufferers from the abovementioned ills the use of the bicycle, and have lost them as patients, the benefit in some instances being immediate, as well as in some chronic cases of headache, constipation, etc.

As a vehicle of convenience one has only to employ it for a short time to appreciate it.

It requires no great physical effort to traverse a mile over level, smooth pavements in from six to eight minutes, and this rate is not wearisome.

I have on a number of occasions arisen at midnight, dressed, and ridden on my wheel to a patient's residence, and arrived there before the messenger did. It is not only a time-saver, but a saver of suffering ofttimes; always ready, night and day; requires no feeding or grooming; is never sick unless its rider is, and soon becomes to its owner a thing of beauty, for which he forms a true attachment.

Where one has any local disease, and is in doubt as to the advisability of his using a bicycle, he should consult his medical adviser prior to deciding.

I have found marked benefit accrue from its employment, it being a provoker to exercise, in those who are disinclined in that direction, as after learning to manage it with ease the necessary physical labor requisite to run it is so slight that many enjoy it who are too indolent to walk or ride horseback. It is a very rapid form of transit, and gives one change of scenery he may have never before known.

I have seen consumptives well progressed in their disease benefited by its gentle and prudent use; their appetites increased, digestive and assimilative powers enhanced, their sleep prolonged and made more refreshing. Its use is an excellent and effective promoter of the skin's action, stimulating the sweat-glands to gentle but emphasized activity. On the latter account riders cannot use too great care against the catching of colds.

In many diseased conditions this activity of the sweat-glands is greatly to be desired, and can be taken advantage of by the physician. The mere suggestion is only necessary.

Where the building-up process is a desideratum, and no contra-indication obtains, gentle exercise on the bicycle will be found of great benefit. It is far preferable to the exhibition of medicaments whose object is to stimulate and tone up the action of the heart, stomach, lungs, skin, and intestinal canal. It gives more of God's medicine (oxygen, sunlight, physical and mental exercise and diversion, self-forgetfulness, etc.) and requires less of the doctor's. To sum up: Rapid riding, or riding long distances at a rapid rate, is injurious in many ways to every rider, unless gradual and careful training has been gone through with that object. Gentle and moderate bicycle-riding increases vitality; improves and enlarges lung and breathing capacity; develops the muscular (general) as well as special systems or sets, as also the heart's power; increases appetite and powers of digestion and assimilation, thereby adding to capacity for life and increased longevity; stimulates action of skin, and thereby elimi