In many cases the disease appears to occur, as it were, spontaneously; in others it is brought on by external violence, cold and damp, or too long-continued, or violent exercise of the joint.

DISEASE OF THE SPINE.-When the bones of the spine become the seat of scrofulous disease, the child becomes languid, listless, disinclined to play or move about, and is quickly tired when he attempts it. He frequently trips and stumbles, and when he moves hastily or unguardedly, his legs cross each other involuntarily, and he is thus often suddenly thrown down. If he endeavor to stand by himself, still and upright, his knees totter under him. He cannot, with any degree of precision or certainty, direct either of his feet to any particular point, but in attempting to do so, one will be brought across the other. He soon begins to complain of frequent pains and twitchings in the thighs, particularly when in bed, and of an uneasy sensation at the pit of the stomach. When he sits upon a chair, his legs are almost invariably drawn across each other, and up under the seat; finally, the child loses entirely the power of walking.

If the disease be in one or more of the cervical vertebræ, the child finds it inconvenient and painful to support his head erect, and is desirous of leaning it on a table or pillow. If seated in the dorsal vertebræ, there is often a hard, dry cough, laborious respiration, and the early occurrence of hectic symptoms. Frequently the arms are affected with spasmodic twitchings, involuntary contractions, and finally, entire loss of motion. When the lumbar vertebræ are affected, there is often difficulty in voiding the urine; the feces will finally be discharged involuntarily. In some cases, the loss of motion in the lower extremities is complete; in other cases, the patients are able to move about with the aid of crutches, or by grasping the thighs just above the knees, with both hands; some can sit in an arm-chair, without much trouble or fatigue; others cannot sit up at all.

The first indication of the disease is, very generally, when the patient is old enough to describe his feelings, a fixed pain in some part of the spine, extending in the direction of the nerves which arise from the affected portion. There is, at the same time, a sense of weakness in the back, and pain in the sides, more marked in one than in the other. Sooner or later there takes place a destruction of the bodies of one or more of the vertebræ, producing an incurvation of the spinal column forwards, and a corresponding projection backwards.

A wasting of the muscles of the back very generally precedes the spinal curvature. The head of the child is then inclined forwards more than natural; one shoulder is raised above the other, and there is a disposition to lean or recline, when the patient is sitting down. This, however, is much more common in cases of lateral curvature, where the bones are not primarily affected, but in which there is simply, in the majority of instances, a want of power in the muscles inserted in the spine. In angular curvature of the spine, on the other hand, there is invariably a destruction of the bodies of one or more of the vertebræ. We have occasionally noticed, however, a wasting of the dorsal muscles to take place early, in cases also of angular curvature. The lateral curvature may, and often does, occur in children

predisposed to scrofula, from defective nutrition of the muscles, but it is not connected, necessarily, with scrofulous disease of the bony structure of the spine.

The spinal cord becomes incurvated with the vertebræ, and subjected to more or less pressure, from which there results, in the progress of the disease, irritation and inflammation of the spinal nerves, chronic inflammation of the membranes of the cord, and occasionally of the cord itself. In some cases the cord becomes so much compressed as to deprive the parts which receive nerves from below the point at which the pressure exists, almost entirely of motion and sensation.

The natural cure of the disease of the spinal structure is by anchylosis, produced by the deposition of osseous matter, so as to attach together the surfaces of sound bone, which are brought into contact. Caries of the spine is very frequently the cause of psoas and lumbar

abscess.

The danger of the disease will depend, in a great measure, upon its extent, the nature of its complications, and the period at which the treatment is commenced. Where only one or two of the vertebræ are affected, and the disease is placed under proper medical care in its early stages, a cure may, in many instances, be effected, and little or no deformity remain. When several of the vertebræ are involved in disease, even though a cure should be effected, very extensive deformity will nevertheless be the consequence, rendering the patient, perhaps, a cripple for life. In those cases in which the disease of the spine is complicated with tubercular disease of the lungs, or with psoas or lumbar abscess, the event is generally sooner or later fatal.

TUBERCULAR DEPOSITIONS.-Under precisely the same circumstances as produce a predisposition to scrofulous disease, and most generally associated with the latter, we find to take place, in the texture of nearly all the organs, as well as upon the surface of the mucous and serous membranes, the formation of tubercles, varying in size and appearance, either in their different stages, or according to the particular tissue in which they occur. Various opinions have been entertained as to their nature and origin, the merits of which it is not our province, on the present occasion, to examine into.

Tuberculous matter has, it is said, been detected in the blood, and hence has been considered to be a morbid constituent of it. It has been plausibly suggested, by Carswell, that this matter is deposited in the tissues during the imperfect process of nutrition which takes place in certain constitutions, or that it is separated from the blood with the secretions.

Rilliet and Barthez, who have given, in the third volume of their work on the diseases of children, the most complete and accurate account of tubercles, as they occur in early life, describe the crude tubercle as a solid, homogeneous mass, of a dull, yellowish-white colorof a somewhat moist consistence, and easily broken or crushed. When broken it exhibits a somewhat granulated surface.

Miliary tubercles consist of quite small granules of a round or oval shape, either perfectly distinct from each other, or collected together

in groups. In the latter case they gradually augment in size, and often form masses of considerable extent, which not unfrequently include a portion, more or less extensive, of the surrounding tissue. The miliary tubercle is most generally enveloped with a vascular network, which, after the tubercle has become considerably enlarged, unites with the surrounding cellular tissue, and forms a kind of fibrous cyst, more or less dense.

Yellow tuberculous infiltration occurs in the form of an irregular mass, the edges of which are confounded with the neighboring tissue, and extend themselves, by irregular prolongations, in different directions. In their neighborhood, irregular tubercles often occur, which sooner or later become united with one of the prolongations of the former. Sometimes the yellow infiltration assumes more or less of a rosy tint, which gives to it the appearance of being traversed by small vessels. The miliary tubercles and yellow infiltration very often, after a time, become confounded; the first by agglomeration, forming large masses, when they can be distinguished from the latter only by the presence of the network of vessels which surrounds them.

Gray granulations occur under the form of very minute bodies, either spheroidal, or oval, or flattened and almost lenticular. They feel to the finger like a small grain, which is with difficulty crushed under the nail. Occasionally they contain a drop of serous fluid. They may, in some cases, be detached readily from the tissue in which they are formed, leaving a small smooth cavity; in other cases they have been found appended to a filament resembling a vessel. Their color is a decided gray; but when removed from the tissue in which they are seated, they appear more clear and transparent. They have this latter appearance in the liver, even when surrounded by the parenchyma of the organ. Their substance is usually homogeneous; occasionally, however, a black point exists in their centre, or they are surrounded by a circle of black matter, disposed in very fine ramifications. They now and then occur in groups of from three to twenty, scarcely separated by the tissue of the organ; thus forming small hard masses. Laennec describes a kind of tubercle as occasionally occurring in the midst of the miliary tubercles, in the form of a fine gelatinous infiltration, either colorless or sanguinolent.

The yellow granulation is a small body, softer, and of a clearer yellow color than the crude tubercle. It has the appearance of a false membrane. It cannot be broken or crushed under the nail. Its form depends on the resistance of the tissue in which it is developed; thus, in the parenchymatous tissues it is rounded, in the serous, lenticular, in the pia mater rounded on the side of the brain, and flattened on the side of the arachnoid. It is invariably surrounded, in the serous tissues, by a network of blood vessels. These granulations occur either distinct from each other, or united in small groups.

Rilliet and Barthez describe, under the name of tuberculous dust, a form of tuberculation, occurring under the appearance of numerous very minute white or yellow points, not sufficiently close together to constitute a continuous yellow surface, but strewed throughout the

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tissue, which is almost invariably the seat of an acute or chronic inflammation, and sometimes of gray infiltrations.

According to Rilliet and Barthez, the origin of the yellow tuberculous matter is either, 1st. The gray granulation which passes into the yellow, and afterwards into the miliary tubercle, or yellow infiltration. The gray granulation may pass also into the gray infiltration. 2d. The gray infiltration, which gives birth indifferently to the yellow granulation, the miliary tubercle, or the yellow infiltration. 3d. The tuberculous dust, which may be the origin of the yellow infiltration. 4th. The yellow granulation, which may appear originally. 5th. The formation from the first of crude yellow matter.

The inflammation, acute or subacute, of the organs, precedes, in a large number of cases, their passage into the condition of the semitransparent gray tissue.

In retracing these facts in a different order, we perceive that the miliary tubercle may occur originally, or in the gray infiltration, or succeed to the granulations, gray or yellow. The yellow infiltration may occur either originally, or in the gray infiltration, or it may result from the union of the yellow granulations or of the tuberculous dust. The large tuberculous masses result from the development and union of the partial infiltrations, or of the miliary tubercles. The crude yellow tubercle succeeds to inflammation only through the intermedium of the semi-transparent gray tuberculous matter, and perhaps of the tuberculous powder.

The yellow tuberculous matter may soften and become reduced to a fluid state, or it may become dry and pass to the stony or cretaceous condition. When the tubercle becomes softened, and an inflammation, followed by suppuration, occurs in the surrounding tissue, there results a cavity varying in extent and form, the parietes of which may be lined with a soft tuberculous tissue, and its cavity filled with a mixture of pus, tuberculous matter, and the debris of the organ in which the cavern is seated.

In the serous membranes, tubercles manifest less tendency to softening than in other situations, and it is a remarkable fact, which Rilliet and Barthez have found to be invariable, that perforation of the serous membranes, resulting from the softening of tubercles, is occasioned by the softening of those seated on their external surface, which also have a tendency to perforate the natural canals with which they are in contact.

More extended consideration of the successive changes which take place in the several forms of tubercles, and the various causes which tend to promote their growth and softening, belongs to a treatise on general pathology.

Tubercles are incapable of organization, but appear to have the power of exciting certain morbid actions in the parts in which they are seated, which affect their own softening, while it produces disorga

nization of the latter.

It has been supposed by some, that in every instance of scrofulous disease, the peculiarities of the latter result from the deposition, in the

affected tissues, of tuberculous matter, modified in its appearance and mode of deposition by the particular structure in which it occurs.

Tubercles may occur, during childhood, in almost every organ and tissue of the body. The most frequent seats of tubercles are, in general, those also where they occur to the greatest extent. These are, in the order of their frequency, the lungs, the bronchial glands— then, at a long distance, the mesenteric or abdominal glands, the small intestines, liver. &c.

As regards the general distribution of tubercles in the different organs, the more nearly children approach the age of puberty, the more generally do we find tubercles limited to the lungs and intestines, and to present the same aspect as in the adult. In younger children, we find, occasionally, all the organs studded with small, gray granulations, which, if united in one organ, would form a considerable mass, but disseminated throughout, they do not profoundly alter any one. Miliary tubercles of a uniform size may occur in all the organs, constituting a larger mass than in the previous case. In a third set of cases, considerable quantities of yellow granulations are present in several organs, causing at times a degree of disorganization which is surprising. These three forms may be partial or general-the latter most frequently partial, the others more usually general. As an almost invariable rule, the number of organs at the same time invaded by tubercles is greater in children than in adults, while certain organs, which at a more advanced age are rarely the seat of tubercles, are particularly so in children.

The pathological influence of tubercles upon the tissue in which they are deposited, it is not easy to understand. They would appear, however, to predispose it to the occurrence of inflammation of a subacute character, and of which it modifies, to a certain extent, the phenomena, progress, and results.

Whether, in any instance, tubercles can be considered as an exciting cause of disease, is uncertain. In numerous instances we have met with them after death, in cases in which, during life, there were no indications to lead us to suspect their existence. They are, more probably, in many cases, the result, rather than the cause of diseased action.

The general symptoms indicative of the existence of tubercles vary somewhat with the organs in which they chiefly occur. Usually, however, there is paleness of countenance, general progressive emaciation and debility, a dry, rough, harsh state of the skin; often repeated desquamations of the cuticle, and oedema of the face, lower extremities, or scrotum. Usually, in the course of protracted cases, hectic fever occurs, with circumscribed redness of the cheeks, evening exacerbations, and more or less profuse night-sweats.

TUBERCULIZATION OF THE BRONCHIAL GLANDS is almost peculiar to childhood. It is a frequent and serious affection, giving rise to symptoms with difficulty distinguishable from those of tubercular phthisis.

The enlarged bronchial glands may act mechanically on the neighboring organs contained in the chest, or they may perforate them.