of lime, and ten and a half parts of carbonate of line, deposited in a gelatinous net-work of cartilage, composing about thirty parts in the hundred of bone. The remaining six or seven parts is made up of phosphate of magnesia, soda, muriate of soda, oxide of iron, oxide of manganese, fluoride of calcium. From all the analyses made it is inferred:

1st. That the quantity of lime contained in the bones of different parts of the body of the same individual, varies considerably.

2d. That the fixed salts are so much the less in proportion as the medullary canals and cavities increase, and accordingly less in the spongy bones than in those more compact. In the spongy bones the membranes and vessels which line the medullary cavities and canal are larger in quantity.

3d. The inorganic constituents increase with age. From early infancy to adult age, the phosphate and carbonate of lime increase (according to Schreyer,) from sixty-three per cent. to sixty-eight.

DISEASED BONE.-Character and Internal Structure.-From a condensation of the observations of Ragsky, Marchand, Ephraim, Nasse, made up by Rokitanski, the following observations are collected:

1. EXOSTOSIS. A compact bony protuberance which appears as a plano-convex knob which has been glued on. It frequently exceeds in hardness and density the bony substance to which it is attached; this, from the commencement of its formation, possesses equal density, so that the very smallest miliary excrescences are as dense as the largest. They never appear spongy, but the newest formed strata soon pass into the state of ivory density. They vary in size from that of a millet seed to that of a hazel-nut; their surface is generally even. Some are also, uneven, but always smooth and apparently polished. Sometimes they grow in the form of a horny knob, and some into a more or less cylindrical form. The color of these compact knobs is white, yellowish white, often whiter than the bone from which they grow.

2. Spongy Exostosis.—A tumor of cellular texture, filled with marrow, and lined by compact lamella, as a covering. It is developed sometimes from the compact-sometimes from the spongy bone; the external covering passes into that of the bone itself. In some cases the spongy exostosis exhibits not only its spongy tissue within the compact external covering, but also a regular medullary cavity which communicates with the proper medullary tube. After the spongy exostosis has continued a consideruble time in its proper structure, the mass increases, a sclerosis takes place in it, in various degrees, and to various. extent; it acquires a compact external covering of considera le density by a stratum of spongy substance, or a regular medullar cavity is enclosed; it becomes also equally compact to a considerable depth in

several places, and in some cases through its whole extent. Accord ing to Valentin and Lassaigne, the quantity of phosphate of lime in an exostosis is diminished (from forty-one to thirty,) while that of carbonate of lime is considerably increased.

3. Osteophyte. This can only be distinguished from exostosis by its appearance as a bony structure, which generally involves extensive portions of a bone, and covers it in various forms. The osteophyte ap pears velvet-like and villous when it covers the bone like a ring, or a stratum from one to two lines thick, which consists of fine fibrils and lamellæ, and thereby pits on the appearance of velvet, or of a fine felt. As it continues to grow thicker, it acquires a smooth external covering, perforated by numerous fine pores, and, at some depth it acquires a lamellated structure. Its color in the recent state is blue, rose-red, inclining to yellow, a dirty white, or of a color blending white with a silken or asbestos-like gloss. The osteophyte presents the splin tery-leaved appearance, when it covers the bone in the form of conical excrescences or lamellæ several lines in length, which, beneath a fine, porous, compact, external covering, contain a large-celled osseous structure, or even one simple cavity. The watery osteophyte forms wart-like excrescences, with a broad, narrow base, consisting of a chalky, white, and very brittle substance. This is most frequently found in the hip-joint, and its arthritic metamorphosis. The osteophyte which appears in the form of smooth, styloid, knotty prolongations, simple or ramified, pedunculated and round, is hard, and of a thick texture. Another form of osteophyte appears in the form of a long mass poured upon the bone; it looks as if it had been solidified, as it were, at the moment of its flowing, with generally an even and a smooth surface; and it is also compact and hard.

4. OSTEITIS.-Inflammation of Bone.-This may arise from external or internal causes, though the latter are more particularly connected with unhealthy states of the system. It has its seat sometimes in the spongy substance.

Phenomena of Osteitis.—A moderate degree of inflammation throws out gelatinous exudation, which passes from a dark-red through the yellow-red into a reddish-white, and ultimately into a white color. In consistence this exudation passes from the gelatinous state to that of a pliant, flexible cartilage, and of a reddish white, succulent bone. This covers the old bone as a scarcely perceptible white porous growth, or as a very fine felt or velvet, and is connected internally with the bone as with the periosteum. When the inflammation is very violent, has occurred repeatedly, or is of a specific and severe character, it gives out more copious exudations of the form above-mentioned, whereby the periosteum is increased sometimes to a fibrous callous of enormous thickness, as is occasionally observed on the front of the tibia. Be

neath the periosteum, the base of the ulceration, there is found a growth or secretion, consisting of curled or straight osseous plates placed on the bone, into the interstices of which the periosteum gives off prolongations. When the inflammation has its seat in the inner lamella of a tubular bone, the medullary cavity is narrowed by the exudation given out. A higher degree of inflammation causes a fibrinous product, or a purulent product, varying from a thin to a thick fluid, of a yellow or reddish color, or a product of a greenish, brownish, discolored and sanious appearance. In such inflammations as run a very rapid course, the periosteum over the bone seems to be displaced, and frequently distended by pus into a fluctuating sack; in correspondence with the effusion which is poured out into all parts of its structure, the bone presents an ash-colored, dirty, yellowish, or reddish, green appearance. In case the effusion is sanious, the surface of the bone is rough and corroded. (Rokitanski.)

"The bones," says B. B. Cooper, "fall more slowly into disease than the softer parts, and their restoration is proportionately more tardy; and hence it is that disease or injury to the periosteum immediately affects the bone itself, a circumstance that must be ever borne in mind by the surgeon when operating upon bones, for it is scarcely possible that any very extensive destruction of periosteum can occur without exfoliation of the bone itself." (Lectures on Osteology.)

Treatment. (See p. 365, Vol. II.)-Whether the inflammation be acute or chronic, common or specific, the strict antiphlogistic regimen and counter-irritants are the usually trusted remedies. But our reliance must be chiefly on Silicea, Calc., Phos., Calc.-carb., Caust., Asafoet. See also Vol. II. pp. 175, 176, 308, 321.

When the inflammation has subsided or terminated by resolution, a thickness of the inflamed bone remains for a considerable time, and the absorption of the adventitious earthy parts can be but slowly ef fected.

When the inflammation goes on to the formation of pus, its existence is indicated by symptoms similar to those which attend on suppuration in the soft parts. Though there are no external symptoms a correct diagnosis will be reached by observing the rigors, with increased sense of weight in the diseased part, and a remission in the severity of the pain.

In abscess the part of the bone affected soon becomes swollen, its periosteum becomes thickened, caries supervenes, and the matter is discharged by a process similar to the discharge of pus from the soft parts; but the progress and reparation are slower.

MORBID STRUCTURES.-1. Formation of Cysts.-The simple cyst, with serous or synovial contents, are found chiefly in the bones of the These, with the compound cystoids, and the acephalocysts, are

face.

The latter have been seen in the humerus, tibia, os-ilium, and in the deploe of the thigh bone. Rokitanski describes a specimen preserved in the Vienna collection in which the left os-ilium was changed into a serous sack as large as a man's fist; and this was filled with numerous pieces of bone of different sizes, adhering to the inner wall of the sack, and with echinococus cysts, some being the size of a millet-seed, some that of a nut.

• 2. Fibrous Tumors.-These sometimes grow to a large size, and in doing it distend the bone to a cyst, or crush it in such a manner that dismembered fragments of bone are found in the substance of the tumor, one part being separated from another. The structure of the fibroid is sometimes thick, sometimes loose, white and elastic.

3. Enchondroma.-This occurs more frequently in the bones than other parts, and is most common in the bones of the fingers, toes, ribs, and sternum. It continues like the permanent cartilages for a long time, even during life in its original state; in some cases it becomes ossified; sometimes it is attacked with inflammation from the sur rounding soft parts, and then it often suppurates. (Rokitanski.)

Osteoid. This is characterized as a bone developing itself from an ossifying cartilaginous element of new structure in the old bone, in the form of a round tumor which is distinguished from the normal bony structure by a different elementary texture. (A case of this disease given by Simon, Med. Chir. Rev., Jan. 1844, p. 97.) Lastly, among the morbid formations have been classed the very rare affections of: choleostoma, tubercle, sarcoma, carcinoma.

Osteo-sarcoma, so called from its resemblance to both bone and fat in texture, often appears in the lower maxillary bone. It begins in the periosteum, or the alveolar socket, and the bone is soon implicated. It generally occurs in depraved habits, and may be excited by extract. ing teeth or by other operations. As the disease advances, the tooth becomes looser and is then a source of irritation. Kocker says it always originates in diseased roots or in the teeth, but this does not appear to be the fact. The remedy in the early stage consists in the removal of the loosened teeth, which will be sufficient. If the disease is more advanced there is no resource but in extirpation.*

5. SOFTENING OF BONES.

OSTEOPOROSIS.-An excessive development of the marrow, or of th tissues which fill the medullary canals and cells of the bone, causes an increase of volume of the bone by rarifying its tissue. The parietes of the dilated interstices of the bone are so much attenuated that gaps

* U. S. Med. Surg. Jour., March, 1836, p. 336.

cr chasms take place at length in the interior and in the external covering, where by the cavities in the bone enter into communication. with each other. The higher the degree of the disease is, the more soft, porous, and spongy the bone becomes, until it yields to the pressure of the finger, and is easily cut with a knife; its spaces become filled with a dark-red medulla which collects in great quantity, and is soon transversed by dilated vessels.

First form of Osteoporosis-Osteo-Malacia.-In this disease the bones diminish in size, and the change consists in osteoporosis with atrophy, a soaking of the bone in fat, and in a reduction of the bone to its cartilaginous element. In this cartilage the bony corpuscles appear empty, the lamellar structure has disappeared; at the same time the cartilage undergoes a peculiar change in its chemical composition, as the general extract obtained by boiling is distinct, both from chondrin and from gelatine of bone. (Rokitanski.)

The chemical changes that occur in the composition of the bones in rickets and osteo-malacia are about the same. The earthy salts are very much diminished; and at the same time five or six times the usual quantity of earthy phosphates is found in the urine. Berzelius showed that phosphate of lime is dissolved rapidly by lactic-acid. As in scrofula and in scrofulous bones an excessive quantity of acid is generated in the prima-viæ, it may be that more acid reaches the circulation than in health, and becomes the cause of the solution of boneearth in the bones. When the quantity of alkaline salts in the blood is too small to saturate the acid, the bone-earth becomes dissolved. This idea may be applied in the treatment of rachitis by a suitable antacid diet, avoiding the articles that form lactic-acid; as sugar starch, and gum. (Marchand.)

Softening of the bones in adults is the result of a specific disease; and is either caused by some specific dyscrasia different from all others, or from some of those well known, as scurvy, syphilis, rheu matism, or of the more terrible vice of the constitution called carcinoma. It seems that in every case of osteo-malacia, before the softening of the bones is observed, some of the above psoric affections have been manifested.

Osteo-malacia begins with deep-seated pains in the bones, progressing slowly. In some cases it is only fully developed in many years, even twenty or more. In general, it does not begin in all bones at once, but by fractions only of individual bones; and it does not progress, like rachitis, from below upwards. Before it is far advanced, some bones are alone involved; and some portions of these will be softened, in direct contact with other parts of the same bones. Many instances have occurred of this in patients suffering from cancer of the stomach, breast, or uterus.