Such a case of rachitical cranial sclerosis I have described in the Amer. Med. Monthly of 1861. It was, however, by no means a mate of the case related by E. Huschke. The latter skull was that of a girl of seventeen years, and weighed 4117 grammes instead of the normal weight of 600 grammes. The medullary (Havers') canaliculi were large and very numerous on the surface, narrow and very few in the interior of the sclerotic bones, and the osseous canaliculi were more spherical and irregular in site and shape. The chemical composition was also abnormal, phosphate of lime being 65.59, carbonate of lime 11.12, sulphate of magnesia 1.14, cartilage and fat (very little), etc. 22.15 per cent. No fluorate of lime was found. Most of the bones were exceedingly hard, but fragile when tried in small pieces; very white inside, yellowish on the surface, the latter color being the remnant of extravasated blood or other pigmentous matter. Another skull, in Huschke's possession, and moderately sclerotic, weighed (lower jaw excluded) 1075 grammes; a third, in the museum of the University of Jena, is that of a young baboon,¹⁴ in which all the bones covering the hemispheres had become sclerotic.

¹⁴ Baboons suffer from rachitis very extensively. In the Transactions of the Pathological Society of London (xxxiv., 1883, pp. 310, 312) I. B. Sutton gives the description of two baboons, one of which was six months, the other one year and six months old, when they died. The careful description of the specimens exhibited leaves no doubt as to the rachitical nature of the changes in both the periosteum and the tissue of all the bones of the body.

Of undoubted total cranio-sclerosis Huschke reports but ten cases—those of Malpighi (1697), Cuvier (1822), Ribalt (1828), J. Forster and Bojanus (1826), Ilg (1822), Kilian (1822), Otto (1822), Vrolik (1848), Albers (1851), Huschke (1858). The disease does not affect the auditory bones, the condyles of the maxillary and occipital bones, nor the styloid process of the temporal bone. It is recognizable in the posterior part of the cranium and basis cranii, but affects mostly the bones of the face and the frontal, parietal, and cribroid bones. Thus, the disease takes its origin in the anterior portion of the skull, particularly in the superior maxilla, and proceeds upward and backward, terminating in the basis cranii in the neighborhood of the infundibulum and appendices. But two of all the cases were observed during life. In all the disease was traced back to early life. The chemical composition of the bones was greatly changed in all. Instead of the normal proportion of earthy to organic material = 2.1 (or 1.5):1, it was from 3.5 to 4.4:1. Particularly the carbonate of lime was greatly increased.

The brain and its meninges participate, in many respects, in the changes worked by rachitis, and mainly in the abnormal vascularization of the bones. They are very much congested, and succulent. A section through the brain shows a great many large and small blood-points. This hyperæmia may give rise to over-nutrition, which assumes the character of real hypertrophy of the brain. When that hyperæmia, however, becomes excessive, effusion will take place into the cavities, the tissue of the arachnoid, and the substance of the cerebrum, which latter looks peculiarly brilliant, elastic, and sometimes white, in consequence of the blood-vessels being emptied by the pressure on the part of the enlarged mass of the cerebrum upon the blood-vessels. Thus, instead of cerebral hyperæmia there may be anæmia. Every form of hydrocephalus may follow the rachitical process. Afterward, when the craniotabes has healed, the secondary effusions will generally also disappear, but not a few cases of hydrocephalus may be traced to rachitis occurring during the first half year of life. When that occurs, the intellectual faculties may suffer, while, on the contrary, complete recovery not infrequently exhibits an unusual degree of mental development, for the same reason which improves the chances of the development of the bone. The degrees of physiological and pathological nutrition and over-nutrition are very variable in their nature and results.

This condition of the cranial contents is not the only one brought about by rachitis. The softness of the cranial bones permits a direct pressure on the brain. The side on which the infant for the most part reposes gets flattened, and the brain is also compressed. The skull consequently bulges out in the opposite direction. This anomaly, as stated above, is sometimes visible through life, though in the large majority of cases after recovery from rachitis has taken place this asymmetry will gradually disappear. Before that can occur, however, the infant is liable to suffer from the rachitical changes. Convulsions are by no means rare. Vogel has, however, been able to produce an attack of convulsions by pressing upon the softened spots of the cranium. Permanent or temporary contractures of the fingers and toes I have seen in several instances. Gerhardt looks upon rachitis as one of the causes of tetany.

A frequent symptom of the cerebral changes which take place during, and in consequence of, craniotabes is the crowing inspiration, or laryngismus stridulus, of infants. It may be mild or severe. The mild form is very frequent, and consists in the occurrence of a shrill inspiratory sound while the baby is either quite placid or excited or crying. It is frequently overlooked entirely, is usually overcome after a number of months, and gives rise to serious trouble in but very few instances. The severe form is of a different nature. While the baby is awake or asleep, without any premonitory symptoms, while playing or crying, placid or excited, all at once respiration will cease. This will take place, usually, after expiration. The limbs are hanging down, as it were lifeless, the face turns pale, then purple, and slight convulsive twitching may set in for ten or twenty seconds. There appears to be a complete paralysis, and death from apnoea seems to be imminent. All at once, a long, deep crowing inspiration will be heard, respiration will commence again, and the whole terrible attack is overcome. It may return a number of times every day, or sometimes not for several days, during a period of many weeks or several months. The attacks which set in after inspiration are apt to be more dangerous. In such an one, but also in the other kind which sets in after the expiratory movement, death may occur suddenly, or the attack may be followed by a convulsion which may terminate fatally like any other eclamptic seizure. In this manner it is that the majority of cases of rachitis perish which terminate fatally during the active progress of the morbid process. In this connection, however, it may be well to add that craniotabes is not the only cause of laryngismus, particularly when the latter is found in the second year of life, or even later. But almost every case, without any exception, which is observed during the first eight or nine months is due to that very cause; and a good many cases occurring later, when the craniotabic bones have become normal, arise from the effects, either meningeal or encephalic, of the rachitic process. Still, complications of craniotabes with a large size of the thymus gland may occur, and enlargements of the tracheal and bronchial lymphatic glands are quite frequent, as we shall see below.¹⁵

¹⁵ Z. Oppenheimer prefers the name rachitic asthma in place of laryngismus, and suggests an explanation of the symptoms from a strictly anatomical point of view. If not correct, it is at all events interesting, as everything this ingenious writer proposes. He points to the ligament situated between the spinæ intrajugulares of the temporal and occipital bones, which, as long as it is of normal consistency, separates the jugular vein from the pneumogastric nerve. As it is covered with periosteum and dura, it is apt to ossify, and forms an osseous partition in the foramen jugulare, which participates in all the changes taking place in the periosteum. As this becomes softened and succulent, so will the ligament, either on both sides or on either. Its influence on the neighborhood depends on its size or succulence (as also on the difference in width of the foramen jugulare or lacerum, which corresponds with the difference in size of the transverse sinuses). The irritation of the pneumogastric is perhaps easily explained thereby, but in very exceptional cases only the accessory nerve would be affected. As, however, the latter controls the sterno-cleido mastoid and trapezius, and also the laryngeal muscles, and is apt to provoke cardiac paralysis during diastole, the occurrence of sudden death would be best accounted for.

While the size of the cranium is normal, or sometimes more than normal, the face undergoes some changes which result in absolute or relative diminution of size. These depend mostly on a reduction in the volume of the jaws. Glisson knew of it, and therefore looked for the cause of rachitis in the process of dentition. Now, both maxillæ are liable to become rachitical at an early date, as early indeed as the bones of the cranium. Rachitical deposits and softening take place in them very generally. The lower maxilla is flat anteriorly, it loses its rounded outline, is shorter in longitudinal direction, while the rami are thick and clumsy; the whole bone is shorter than normal, and sometimes asymmetric. Its changed appearance is greatly due to the effect the muscles, with their powerful insertions, produce on the softened bone; mainly the masseter, also the mylohyoid, which draws the lateral portions inward, and the geniohyoid, which pulls at the central portion. Of the latter, the lower portion is drawn out, the inner and the alveolar part inward. Thus, the teeth, mainly the incisors, of the lower jaw are turned inward to such an extent that, as those of the upper look outward, the two rows of teeth do not touch but cover each other. Besides, the periosteal proliferation around the alveoli is excessive, sometimes so much so as not only to crowd the teeth into irregular positions, but even to absorb and annihilate alveolar processes in the course of the morbid changes. The cases in which the number of teeth are actually diminished by rachitis are not at all rare. In the superior maxilla the last-described anomaly is also observed. Periosteal thickening is mainly noticed about the intermaxillary bone—sometimes to such an extent that above and behind it a considerable impression takes place. The shape of the upper jaw is more spherical than normal, and the cheek-bones become very prominent.

The belief that maxillary rachitis is now and then met without any other symptom of rachitis I do not share. What I said of craniotabes is also valid in regard to this form.

Irregular teething is a constant companion of maxillary rachitis, but is also present where the latter is not well, or not at all, marked. As a rule, the first teeth protrude late, about the ninth or tenth or twelfth month. That the first year and more should elapse without any tooth is of frequent occurrence in rachitis. Cases in which the first teeth do not come before the second year is completed are not very uncommon; in some there are none even when the child is much older. In most cases the retardation of dentition goes hand in hand with very marked retardation in the development of the rest of the bones and in the closure of the cranial fontanel. But not in every case of rachitis is there a retardation in the process of teething. In some a few teeth appear at the regular period (at the completion of the seventh or eighth month), or even at a very early age (in the fourth or fifth month); after which there is an interruption in the protrusion of teeth for an indefinite period. Evidently, the period in which rachitis is developed exerts its influence on the teething process. When it exists at a very early age, it will retard teething until recovery takes place. Still, it is possible that a moderate amount of periosteal and osteal hyperæmia and over-irritation matures the teeth abnormally. In all those cases, however, in which rachitis does not occur before the second half of the first year, the first teeth will appear at the normal time, and a long period will follow in which no teeth at all will make their appearance. Then, again, when the whole process comes to a standstill, and recovery takes place with solidification of the bones, and even eburnation, the teeth will come in rapid succession. Whether they will, as is frequent, decay almost as soon as formed, or whether they will be unusually hard, solid, and yellowish, depends on the stage of the disease in which they made their appearance, and on the complications aggravating the case. Of very grave import in this respect are digestive disorders before and during the course of the disease.

The vertebral column suffers also. In the normal infant it is straight, but in the rachitic it exhibits a kyphotic deformity very soon. When such a baby of three or six months is sitting up, the middle portion of the back is protruding, as in Pott's disease. In almost every case, however, this kyphosis is but apparent and the result of muscular debility. In order to arrive at a diagnosis at once, it is sufficient to place the patient on his face and support the head, and raise the lower extremities and pelvis in the air. If the kyphosis is but functional, the prominence disappears at once. By nothing can the muscular insufficiency of early rachitis be better demonstrated than by this little experiment. But actual deformity is also found in rachitis. It softens both the vertebræ and intervertebral cartilages, and either their anterior or posterior portion may be irregularly developed, and be either too high or too low. Besides, the articulating surfaces are sometimes too convex. Thus the causes of both kyphosis and scoliosis are amply furnished, and complications of the two are quite frequent, and the deformities resulting therefrom quite formidable. Scoliosis is mostly to the left; kyphosis generally complicated with lordosis, and sometimes the vertebral column exhibits a spiral shape.

The ribs of the convex half are prominent and divergent, those of the concave side flattened and parallel. The two halves of the chest are therefore very unequal indeed. Muscular traction, atmospheric pressure, the elastic traction of the lungs, the presence of pulmonary complications, and the pressure from below on the part of the enlarged viscera of the abdominal cavity, come also in for a considerable share in the completion of the deformity.

The ribs and the sternum aggravate it considerably. Even without any affection of the vertebral column they suffer seriously from the general affection. The manubrium is thickened and drawn inward, the ensiform process protuberant, the sternum often swelled and painful to the touch. The ribs are sensitive to the touch on one or both sides. The child cries when taken up or when fearing to be taken up. The costo-cartilaginous junctures are thickened, mainly so from the fourth to the eighth ribs. The insertion of the diaphragm becomes soon perceptible by a deep groove around the chest. The anterior portion of the ribs is flattened, posteriorly they are inserted at acute angles. Thus the intrathoracic space becomes narrow, the sternum with the costal cartilages is pressed forward (pigeon breast, pectus carinatum), the thorax is deprived of its elliptical shape and becomes triangular, the dorsal aspect being flattened, and the distance between the vertebral column and the sternum increased. Below the diaphragmatic groove the thorax expands, the liver and other abdominal organs crowding the ribs outward. All sorts of changes are experienced by the ribs in these conditions. Parts of them are flattened, parts undergo infraction, parts are even concave; they are bent and twisted, now and then to such an extent as to turn the concave side out, the convex surface in. In addition to all this, the scapula is big and clumsy and protuberant, the clavicle considerably bent and frequently infracted, and not rarely covered with genuine callus.

That the respiratory and circulatory organs must suffer from such anomalies, though they be not excessive, is certain. The heart is crowded by the flattening of the ribs and the contraction of the thoracic cavity. Its beat is visible over a large surface, and its percussion dulness is extended over its normal space, though no enlargement have taken place. This, however, is very apt to occur after some time by overexertion. The latter is increased by the condition of the respiratory organs. The ribs being flexible, the chest contracted and compressed, the diaphragm raised, the respiratory muscles feeble, respiration is insufficient, even without the presence of any further complications; thus dyspnoea and a certain amount of cyanosis are frequently met with in consequence of the anatomical changes only. In addition to this, there is from the beginning a tendency to catarrhal and inflammatory conditions. Even without any deformity the rachitical process is accompanied from an early time with bronchial and tracheal catarrh. A chronic cough in an infant, with very little or no fever, disappearing and returning, mostly with copious secretion—which, however, is swallowed as soon as it reaches the pharynx—rouses the suspicion of general rachitis. It is often complicated with extensive dulness over the manubrium sterni, due (to rachitical thickening of this bone and) mostly to the persistence of a large size of the thymus gland; and also with enlargement of the bronchial and tracheal glands, the latter of which are often accessible to recognition by percussion. They are to be looked upon as a frequent occurrence in rachitis, though no associated diseases leading to their enlargement have been noticed. They and the chronic tracheo-bronchial catarrh are closely dependent upon each other. They are each other's both cause and effect. Neither of them, however, remain uncomplicated. Catarrh grows into broncho-pneumonia, with frequent returns. Atelectasis, interstitial pneumonia, dilatation of bronchi, and pulmonary consumption are often traceable to such apparently slight catarrhs, which, when not recognized as depending on their constitutional cause, cannot be removed. Nor are the cases of miliary tuberculosis, resulting from caseous degeneration of rachitical glands, very exceptional.

The anatomical changes in the abdominal viscera may be due to the preparatory diseases or the complications of rachitis; but, at all events, the abdomen yields a number of changes visible through the whole duration of rachitis. It is very large; its size is due to the contraction of the thoracic cavity and the downward pressure of the chest-wall upon the contents of the abdominal cavity. It is also due to the changes wrought by rachitis in the pelvis. Softening of bones and synchondroses, torsion, the weight of the trunk, and the pressure of the femora from below produce the change of the pelvis so well known and much feared in the parturient female. The promontory and sacrum are pushed in, the arcus pubis is large, the pelvis asymmetric; the small pelvis is contracted, the large pelvis broader. Thus, the small pelvis has no room for viscera, which, then, are crowded upward. The digestive disorders which gave rise to, or formed the first stage of, rachitis result in the accumulation of gas; the scrobiculus cordis is greatly expanded. The liver¹⁶ is large, congested, and in fatty degeneration. The latter is the more frequent the more a certain degree of fatty condition is a normal attribute of every infant liver. When the liver is found but small in post-mortem examination, it is so because of the general anæmia and emaciation. Sometimes it is amyloid, as are also the spleen (mostly hyperplastic only), the kidneys, and the arteries of the intestines in many instances.

¹⁶ Dr. Norman Moore presented a cast and drawing to the Pathological Society of London (Trans., vol. xxxiv., 1883, p. 185) showing how considerable may be the digressions of the diaphragm and local pressure upon the liver in a case of rickets. Three large beads caused as many projections from the under side of the diaphragm, and corresponded with local thickenings of the capsule of the liver, probably produced by the continued pressure through the diaphragm of the beads, which were on the seventh, eighth, and ninth ribs, and the largest of which was equal in size to a hazel-nut.

The alimentary tract is the seat of many changes recognizable during life. The tonsils are often large. The tongue is seldom coated to an unusual degree. On it are found little islands, red, marginated, deprived of epithelium. They will increase in size and number and extend backward. They will heal and reappear. They are by no means syphilitic, as Parrot would have it, and correspond exactly with the erosions near the solitary glands and those of Lieberkühn in the intestinal part, which mean nothing else but a nutritive disorder of the epithelia, and give rise to nothing worse than incompetency of absorption in that locality and abnormal secretion. The stomach is in a condition of chronic catarrh, sometimes dilated. Acid dyspepsia is frequent. Anorexia and bulimia will alternate. Feces contain an abnormally large amount of lime. Diarrhoea and constipation will follow each other in short intervals. The former owes its origin to faulty ingesta or chronic catarrh; the latter, sometimes to improper food, but more generally to muscular insufficiency. This condition has not been estimated at its proper value. Besides myself,¹⁷ nobody but Bohn has paid the attention to it which it deserves. Here, again, I have to insist that rachitis is a disease of the whole system, and not exclusively of the bones. Indeed, the muscular system is amongst the first to suffer. In the same way in which the voluntary muscles are not competent to raise and support the head or to allow a baby to sit up without a functional kyphosis, the involuntary muscles of the intestine are too feeble for normal peristalsis. The infant of a month or two months of age may have had normal and sufficiently numerous evacuations; gradually, however, constipation sets in; the feces become dry, but are perhaps not much changed otherwise. If no other cause be apparent, the suspicion of rachitical constipation is justified. Seldom, however, after it has lasted some time—and only after some time has elapsed relief will be sought—it will remain alone. Other symptoms of rachitis will turn up and the case be easily recognized. This constipation is an early symptom, as early as thoracic grooving or craniotabes. Very often it precedes both—is, in fact, the very first symptom—and ought therefore be known and recognized in time.

¹⁷ Jour. Obst., etc., Aug., 1869.

The kidneys have been mentioned above. They are often found rather large. Though the fact has been alluded to before, I will here again state that it has always been the general impression that the amount of lime eliminated in the urine of rachitic children is excessive. The reverse of that is true. Seemann and Lander have proved beyond dispute that in most stages of rachitis there is less than the normal amount of lime in the urine. Thus, the theory that lime is eliminated by an excess of acids in the blood is proven to be incorrect. But it is a fact that the rachitical bone contains a proportionately small amount of lime. The conclusion is, then, that its introduction must have been diminished. On the other hand, every article of food contains a large amount of lime, which might be introduced into the circulation if digestion be not at fault. The fact is, that a large amount of lime introduced is not utilized, and is eliminated with the feces.

In connection with these facts the following will be found very interesting. It has been found by Bunge that when potassium, with the exception of chloride of potassium, meets chloride of sodium, the two will exchange their acids, so as to form chloride of potassium and phosphate of sodium. They will be found in the blood also, will be eliminated as such, and result in a comparative absence of chloride of sodium from the serum of the blood. Now, comparative absence of chloride of sodium diminishes the possibility of the development of hydrochloric acid. Thus, it is not a surplus of acid, but a lack of hydrochloric acid, which results from such chemical combinations. If such be the case, calcium salts are not absorbed sufficiently. Thus, they will appear in the feces, and not even be absorbed in the intestines, because of the alkalinity of the intestinal secretion, by which the lime cannot be dissolved. The more lime, then, is introduced under these circumstances, the greater the incumbrance to digestion.

The correct proportion between chlorine, phosphorus, potassium, and sodium is certainly exhibited in woman's milk. There is lime enough in even the poorest article of that kind. But indigestion brought on by woman's milk in a disordered condition or by any other cause will prevent the absorption of lime when a superabundance of phosphorus and potassium disturbs the formation of hydrochloric acid. In these cases not only the development of the bones, but also that of the muscles, is disturbed. The latter is of great importance in regard to circulation, because a large part of the circulation depends on the pressure on the part of the muscular fibres exerted on the small blood-vessels. These facts have been the reason why I insist upon the addition of chloride of sodium to the food of infants and children, particularly those who are fed on cow's milk; for cow's milk and vegetables contain a relative superabundance of potassium compared with sodium. Even adults will find cow's milk very much more digestible by adding table-salt to it.

The extremities begin to suffer at a later period than the ribs and cranium. The opinion of Guérin, that the rachitical process begins in the lower extremities and ascends gradually, is erroneous. It cannot even be stated that the lower extremities are affected sooner than the upper. There is no regularity at all; it is not even necessary that all the osseous tissue should fall sick. But this can be taken as a fact, that hands and feet, and particularly the phalanges, are the latest to undergo the rachitical change. First in the line of morbid alteration of the bones are the epiphyses, mainly of the tibia, fibula, radius, and ulna. Their integument appears to be thin; now and then the cutaneous veins are dilated. The periosteum of the diaphysis becomes thick, softened, and painful to the touch and pressure, its compact layer thin, the medullary space large, the whole bone flexible, at the same time that the ligamentous apparatus of the joint becomes softened and flabby. At this time babies are greatly admired and applauded for the facility with which they introduce their feet into their mouths. For at the same time the bones begin to curve under the influence of the flexor muscles, which are always stronger, as they do in later months under the weight of the body when the child begins to walk. The curvature is not always a mere arching, but sometimes the result of infraction (green-stick fracture), a complete fracture not being accomplished because both of the softness of the osseous tissue and the resistance on the part of the thickened and softened periosteum. Both the legs and forearm bend on the external side, the resulting concavity looking inward. The humerus bends in a direction opposite to that of the forearm; the thigh, usually outward and forward.

The attempts at locomotion are often the causes of quite preposterous anomalies; creeping, sliding, walking, turn the extremities in such unexpected directions that talipes valgus, genu valgum, and now and then double curvatures, are the results. These, however, may not always be very marked, but there is one change in the rachitical bone which is constant—viz. the impairment of longitudinal growth. In every case the diaphyses remain abnormally short, and the proportion of the several parts of the body are thereby disturbed. Chiari measured parts of the skeleton of a rachitical woman of twenty-six years who was nine years old before she could walk. Her height was 116 centimeters, the length of the lower extremities 42, femur 23, tibia 15, fibula 20, humerus 16, right radius 12.5, left radius 11, right ulna 15, left ulna 14 centimeters. In a second case the parts of the skeleton were measured after they had been extended with great care. The right arm from the acromion to the middle finger (incl.) was 39 centimeters, the left 38; the right lower extremity from the trochanter to large toe (incl.) 39, the left 41.

The skin participates in the general nutritive disorder. It is soft and flabby. In those infants who become rachitical gradually while proving their malnutrition by the accumulation of large quantities of fat, it exhibits a certain degree of consistency. When rachitis develops in the second half of the first year or later, with the general emaciation the skin appears very thin, flabby, unelastic. The veins are generally large. Complications with eczema and impetigo are very frequent; where they are found the glandular swellings of the neck and below are still more marked than in uncomplicated cases. Circumscribed alopecia is sometimes found (not to speak of the extensive baldness of the occiput). It is not attended with or depending on the microsporon Audouini, but the result of a tropho-neurosis. In the hair Rindfleisch found fat-globules between its inferior and central third. Then it would break, the axial evolution would cease, and the end become bulbous by the new formation of cells.

Acute Rachitis.

There is a form of rachitis which may be, and has been, called multiple epiphysitis or multiple periostitis of the articular ends of the long bones. The changes which in the usual form of rachitis require months to develop take place in a very short time. Not infrequently the children were quite well before they were taken with this peculiar affection. Cases have been known to occur between the fourth and twenty-fourth months of life, and to last from two to six weeks, or just as many months. They have been known to get well, or a few of them terminate fatally. They are accompanied with fever and rapid pulse, perspiration, now and then with diarrhoea, with eager or reduced appetites. At the same time the epiphyses swell very rapidly, and are painful. The same is true of the diaphyses and the flat bones of the head. Many authors do not recognize this form as an independent variety. Some call it an acute initial stage of certain cases of rachitis, as they are not infrequently found in infants which exhibit a very rapid growth. Some have taken it as an independent disease, developed on the basis of a constitutional disposition; some look upon it as a very intense acute form of rachitis; others, as an intense growth of the osseous tissue only. Others call it an inflammation of the bone. Some refer it to hereditary syphilis, and a few to the influence of malaria. That the disease is epiphysitis and periostitis there is no doubt. I do not hesitate to claim it as rachitis, for epiphysitis and periostitis of early age not of rachitical basis are not apt to run such a favorable course as this form frequently does. The cases complicated with subperiosteal hemorrhages are claimed as scurvy by Th. Barlow.

The differences of opinion would probably not have been so great if every author had seen all the cases of the other observers. It will not do to judge of unobserved cases by the light shed by a single case under one's own observation. I have seen cases of acute rachitis which were the initial stages of general rachitis, and have observed those of local or multiple epiphysitis, mainly after infectious fevers, which were diagnosticated as such. They are, however, very uncommon. But even without a preceding infectious fever, such as scarlatina or more frequently typhoid fever, there are unexplained cases of rachitis and deformity. Thus, R. Barwell had some before the Pathological Society of London,¹⁸ which are positive proofs that some forms of ostitis may occur and result in the most formidable deformities without being rachitical. A girl of seventeen years was perfectly well formed up to the age of two and a half or three years. After that time the deformities began to develop, and did not change after she was thirteen, at which time the author saw her the first time.

Her bones were always very brittle. When she was between nine and thirteen she broke her arms four times and her lower limbs on several occasions. A male patient of twenty-two years, who was born healthy and well formed, continued thus until five years of age, when he was attacked with a fever, after which his bones became soft and bent. Osteotomy was performed on him, and the femora were found to be mere thin shells of bones surrounding cavities containing great quantities of medulla, which flowed out of the wound as oil; five ounces were discharged at once. In both cases there appeared to be a hypertrophy of the medulla at the expense of the bone-substance—a condition which Barwell proposes to call eccentric atrophy. "While these subjects are still youthful very little bone-earth is deposited, or at least remains in the very thin layer of osseous tissue that subsists. The relationship between infantile ostitis and extreme development of the intraosseous fat, though well known, is still occult; neither should we lose sight of the possibility that the softening process of ostitis may be due to a fatty acid. Now, fatty ostitis usually occurs in epiphyses. In these cases the shafts were affected."

¹⁸ Trans., xxxiv., 1883, pp. 203-208.

PROGNOSIS.—The course and the prognosis of rachitis are, as a rule, favorable, but they change according to the degree and locality of the affection and the age of the patient. Generally there is neither fever nor rapid exhaustion. But the process lasts for months and even years. In favorable cases, when recovery takes place the teeth will grow faster, the bones become firmer, the epiphyses will diminish in relative size, the bowels become regular. But the length of the bones is, and remains, reduced, and the head remains large as compared with the length of the body. Not only are the bones of normal firmness, but the compact substance undergoes a process of hardening called eburnation by Guérin. The internal organs also become very active, perhaps because the total amount of blood has to supply only a body less extended in length. Nor does the brain suffer after complete recovery has taken place. On the contrary, it appears that the somewhat more than normal vascular dilatation, which under unfavorable circumstances leads to effusion, is frequently apt to nourish the organ of intellect up to a higher standard. In all cases of rachitis, however, the curvatures of the extremities will not disappear altogether, while mild ones, it is true, are hardly recognizable in advanced age. Curvature of the ribs and of the vertebral column, however, will remain, and interfere with the expansion and the normal functions of the lungs and heart. In regard to the lungs, it appears that in many cases they do not find sufficient space to expand. As far as the heart is concerned, it touches the flattened, no longer elliptic, chest-wall over a larger surface, and is very apt to give rise to the suspicion of enlargement in consequence of extended dulness on percussion. The rachitic pelvis is well known to the obstetrician for the difficulties it gives rise to during parturition.

Thus, the prognosis would, as a general thing, be sufficiently favorable if it were not for the number of complications or severe symptoms. The chronic catarrh of the lungs accompanying rachitis, the enlargement of the tracheal and bronchial glands and the lymphatic glands in general, are apt to lead to inflammatory disease of the lungs, which, after having returned several times, leads to infiltration of the lungs with caseous deposits, and not infrequently results in phthisis. The nervous symptoms accompanying craniotabes may prove very dangerous. Spasm of the larynx and laryngismus stridulus may prove fatal in a single attack by suffocation, or general convulsion may set in during an attack of laryngismus or without it, in which the child may perish. Therefore the prognosis in every case of laryngismus and in every case of craniotabes has to be very guarded. It is my rule to wait from six to eight weeks before giving expression to a decided prognosis, because during that time medicinal and dietetic treatment will probably have resulted in such an improvement of the symptoms and condition as to render the prognosis more favorable. Under no circumstances, however, ought we to lose sight of the fact that, though rachitis may disappear, the causes leading to it may still linger on. Defective nutrition, diseases of the lungs, and intestinal affections which gave rise to or accompanied rachitis will complicate the prognosis, though rachitis itself, as far as the bones were concerned, be no longer in existence.

TREATMENT.—To meet the cause of a disease by preventive measures is the main object and duty of the physician. He thus either obviates a malady or relieves and shortens it. Now, if the original disposition to rachitis, as has been suggested, is to be looked for in early intra-uterine life, when the blood-vessels begin to form and to develop, we know of no treatment directed to the pregnant woman or uterus which promises any favorable result. But the more we recognize an anatomical cause of the chronic disorder, the more we can appreciate the influence upon the child of previous rachitis in the mother, and are justified in emphasizing the necessity on the part of the woman to be healthy when she gets married, and to remain so while she is pregnant. After the child is born the most frequent cause of rachitis is found within the diet or the digestion of the patient. To attend to the former is in almost every instance equal to preventing disorders of the latter; for most of the digestive disturbances during infancy and childhood are the direct consequences of errors in diet. It is, however, impossible to write an essay on infant diet in connection with our subject. I have elaborated the subject in my Infant Diet (2d ed. 1876), in the first volume of Buck's Hygiene, and of C. Gerhardt's Handbuch d. Kinderk. (2d ed. 1882). Still, the importance of the subject requires that some points should be given, be they ever so aphoristic.

The best food for an infant, under ordinary circumstances, is the milk of its mother. The best substitute for the mother is a wet-nurse. Woman's milk ought not to be dispensed with when there is the slightest opportunity to obtain it, particularly when the family history is not good and nutritive disorders are known to exist, or to have existed, in any of its members. When it cannot be had, artificial food must take its place, and it is in the selection of it where most mistakes are constantly made. This much is certain, that without animal's milk no infant can or ought to be brought up; as ass's milk can be had only exceptionally, and dog's milk, which has been said to cure rachitis, is still less available, the milk of either goat or cow must be utilized. The former ought not to be selected if the latter is within reach, mainly for the reason that it contains, besides other objectionable features which it possesses in common with cow's milk, an enormous percentage of fat. Cow's milk differs in this from woman's milk, that it contains more fat, more casein, more potassium, and less sugar than the latter, and that its very casein is not only different in quantity, but also in chemical properties. Even the reaction of the two milks is not the same, woman's milk being always alkaline, cow's milk often either neutral or amphoteric, and liable to acidulate within a short time. Thus, the dilution of cow's milk with water alone yields no equivalent at all of woman's milk, though the dilution be large enough to reduce the amount of casein in the mixture to the requisite percentage of one, and one only, in a hundred. The addition of sugar (loaf-sugar) and of table-salt, and sometimes alkali (bicarbonate of sodium or lime-water, according to special circumstances), is the least that can be insisted upon. Besides, the cow's milk must be boiled to prevent its turning sour too rapidly, and this process may be repeated to advantage several times in the course of the day. Instead of water, some glutinous substance must be used for the purpose of diluting cow's milk. As its casein coagulates in hard, bulky curds, while woman's milk coagulates in small and soft flakes, some substance ought to be selected which keeps its casein in suspension and prevents it from curdling in firm and large masses. Such substances are gum-arabic, gelatin, and the farinacea. Of the latter, all such must be avoided which contain a large percentage of amylum. The younger the baby, the less is it in a fit condition to digest starch; thus arrowroot, rice, and potatoes ought to be shunned. The very best of all farinacea to be used in diluting cow's milk are barley and oatmeal. A thin decoction of either contains a great deal of both nutritious and glutinous elements, the former to be employed under ordinary circumstances, the latter to take its place where there is, on the part of the baby, an unusual tendency to constipation. The decoction may be made of from one to three teaspoonfuls of either in a pint of water; boil with a little salt, and stir, from twelve to twenty minutes, and strain through a coarse cloth. It ought to be thin and transparent. Then mix with cow's milk in different proportions according to the age of the baby. Four parts of the decoction, quite thin, and one of milk (always with loaf-sugar), for a newly-born, equal parts for an infant of six months, and gradual changes between these two periods, will be found satisfactory. Whenever there is a prevalence of curd in the passage the percentage in the food of cow's milk must be reduced, and now and then such medicinal correctives resorted to as will improve a disturbed digestion. Care ought to be taken lest for the newly-born or quite young the preparations of barley offered for sale contain too much starch. The whiter they are, the more unfit for the use of the very young, for the centre of the grain contains the white and soft amylum in preference to the nitrogenous substances which are found near the husk. Thus, it is safest to grind, on one's own coffee-grinder, the whole barley, but little deprived of its husk, and thus secure the most nutritious part of the grain, which is thrown out by the manufacturer of the ornamental and tidy packages offered for sale. But very few cases will ever occur in which the mixtures I recommend will not be tolerated. In a few of them, in very young infants, the composition recommended by Meigs¹⁹ has proved successful. It consists of three parts of a solution of milk-sugar (drachm xvij¾ in pint j of water), two parts of cream, two of lime-water, and one part of milk. For each feeding he recommends three tablespoonfuls of the sugar solution, two of lime-water, two of cream, and one of milk: mix and warm. The baby may take all of it, or one-half, or three-fourths.

¹⁹ In Med. News, Nov. 28, 1882.

The recommendations given above are based on a long experience, and the simplicity, cheapness, and facility of preparation of the articles. The substitutes offered for sale under the title of infant foods are in part worthless, all of them expensive when compared with the simple articles recommended by me, and not recognizable as to their uniformity and compounds. But no matter how appropriate my mixture may be, it is always for the young infant to be considered as a makeshift. It is to be used as a representative of mother's milk only when this cannot be had. Therefore it is better to alternate with breast-milk when this is secreted in but an insufficient quantity. Some good breast-milk is better than none at all; but with this proviso, that it is good. There are some milks either too watery or too dense and white. The former will produce diarrhoea, the latter hard and dense curd. The former may be improved by feeding and strengthening an anæmic and overworked mother; the latter, by giving the baby, before each nursing, a tablespoonful of a mixture of barley-water and lime-water, or, when it produces constipation, lime-water and thoroughly sweetened oatmeal-water. The cases in which breast-milk, such as can be had, is not digested by the infant are rare, but they will occur. In them the proper substitute will yield a better result than mother's milk; for mother's milk will not always be a boon, and must then be dispensed with. Particularly is this so when it is too old. Weaning ought to take place when the first group or the first two groups of teeth have made their appearance. After that time mother's milk is no longer the proper food, and instead of preventing indigestion and sickness it is a frequent cause of them and of rachitis. Instead of muscle, it will then give fat, and the large fontanels and big head, the paleness of the rotund cheeks, the flabbiness of the soft abdomen and thighs, will tell the story of rachitical disease slowly engendered by the persistent employment of an improper article of food. I cannot insist too often on this, that rachitis may develop with increasing weight, and that the use of the scales alone is no means of ascertaining the healthy condition of a baby. As much harm, therefore, can be done by weaning too late as by so doing too early or too abruptly.

At that early age we treat of here, digestive disorders are more frequently the results of improper diet than of a primary gastric disturbance. But when the latter is once established it furnishes its own indications. A frequent occurrence, together with a general gastric catarrh, is the presence of fat acids in the stomach, such as an improper amount of lactic, acetic, butyric, etc. acids. Before digestion can be anything like normal they must be neutralized. For that purpose calcined magnesia, carbonate and bicarbonate of sodium, prepared chalk, and lime-water have been found useful. The latter, as it contains but a trifle of lime, in order to neutralize must be given in larger doses than is usually done; a tablespoonful contains but a quarter of a grain of lime. And all of the alkalies must not be given in the food only, but also between meals. For when given in the former way alone it neutralizes the abnormal and injurious acids, together with the normal digestive secretion, the lactic and muriatic. Not infrequently, when the infants have suffered for some time, general anæmia will set in, and result in diminishing the normal secretions of the mucous membranes (and glands). In those cases which do not produce their own gastric juice in sufficient quantity or quality pepsin and muriatic acid may be given to advantage. In these cases the plan suggested by me is particularly favorable—viz. to add a fair amount of chloride of sodium (one-half to one drachm daily) to the infant's food. Also that of I. Rudisch referred to by me previously,²⁰ who mixes one part of dilute muriatic acid with two hundred and fifty of water and five hundred of milk, and then boils (one-half teaspoonful of dil. mur. acid, one pint of water, one quart of milk). Again, there are the cases in which wine and the bitter tinctures, which are known to increase the secretion of gastric juice, render valuable service. The addition of bismuth to any of the proposed plans is quite welcome. As a disinfectant and a mild cover on sore and eroded mucous membranes it has an equally good effect.

²⁰ Am. Jour. Obstet., July, 1879.

Under the head of roborants we subsume such substances, either dietetic or remedial, which are known or believed to add to the ingredients of the organism in a form not requiring a great deal of change. Rachitical infants require them at an early period. Meat-soups, mainly of beef, and of mutton in complications with diarrhoea, ought to be given at once when the diagnosis of rachitis becomes clear or probable. Any mode of preparation will prove beneficial; the best way, however, is to utilize the method used by Liebig in making what he called beef-tea. A quarter of a pound of beef or more, tender and lean, cut up finely, is mixed with a cup or a tumbler of water and from five to seven drops of dilute muriatic acid. Allow it to stand two hours and macerate, while stirring up now and then. This beef-tea can be much improved upon by boiling it a few minutes. It may be given by itself or mixed with sweetened and salted barley-water or the usual mess of barley-water and milk which the infant has been taking before. Older infants, particularly those suffering from diarrhoea, take a teaspoonful of raw beef, cut very fine, several times a day. It ought not to be forgotten, however, that the danger of developing tænia medio-canellata from eating raw beef is rather great. Peptonized beef preparations are valuable in urgent cases.

Iron must not be given during any attack of catarrhal or inflammatory fever. The carbonate (cum saccharo) combines very well with bismuth; a grain three times a day, or less, will answer well. The citrate of iron and quinine (a few grains daily) can be given a long time in succession. The syrup of the iodide of iron (three times a day as many drops as the baby has months up to eight or ten), in sweetened water or in sherry or malaga, or in cod-liver oil, acts very favorably when the case is, as so frequently, complicated with glandular swelling.

Cod-liver oil, one-half to one teaspoonful or more, three times a day, is a trusted roborant in rachitis, and will remain so. Animal oils are so much more homogeneous to the animal mucous membrane than vegetable oil that they have but little of the purgative effect observed when the latter are given. The former are readily absorbed, and thus permit the nitrogenous ingesta to remain in store for the formation of new tissue, but still affect the intestinal canal sufficiently to counteract constipation. As the latter is an early symptom in a peculiarly dangerous form of rachitis, cod-liver oil ought to be given in time (in craniotabes). Diarrhoea is but seldom produced by it; if so, the addition of a grain or two of bismuth or a few doses of phosphate of lime (one to four grains each) daily, may suffice to render the movements more normal. There are but few cases which will not tolerate cod-liver oil at all. The pure cod-liver oil—no mixtures, no emulsions—ought to be given; the large quantities of lime added to it in the nostrums of the wholesale apothecaries embarrass digestion and bring on distressing cases of constipation. These mixtures have been prepared and are eulogized on the plea of their furnishing to the bones the wanting phosphate of lime. The bones, however, as we have seen before, are not grateful enough to accept the service offered. But only a certain amount of phosphate of lime is useful in rachitis and in digestive disturbances. In small doses it neutralizes acids like other alkalies; its phosphoric acid combines with sodium very easily, and gives rise to the formation of glyco-phosphoric acid, which is of very great importance in the digestive qualities of the upper portion of the small intestines.

Plain malt extracts will be well tolerated by some older children. The preparations which are mixed with a goodly part of the pharmacopoeia by generous manufacturers are to be condemned.

Craniotabes requires some special care in regard to the head. The pillow ought to be soft, but not hot; no feather pillow is permitted. The copious perspiration of the scalp requires that it should be kept cool, the perspiration wiped off frequently to avoid its condensing into water, and the flattening side of the head may be imbedded in a pillow with a corresponding depression. Copious perspiration indicates the frequent washing with vinegar and water (1:5-6). The muscular debility commands great caution. The baby must not be carried on the arm, but on a pillow which supports both back and head, or in a little carriage. No sitting must be allowed until the back will no longer bend to an unusual degree. No walking must be encouraged at any time. The patients will walk when their time has come. The bones are so fragile that great care is needed sometimes not to fracture or to infract them and to avoid periosteal pain in lifting. The skin must undergo some training by gradually accustoming the little patient to cool water. It can be readily, but gradually, reduced to 70° for a bath at any season. The addition of rock- or table-salt to the bath is a welcome stimulant. And fresh air ought to be granted freely.

Laryngismus stridulus shares the indications for treatment furnished by craniotabes. The general treatment remains the same. Prominent symptoms and complications ought to be treated besides; constipation requires the more attention the more convulsive attacks of any description may arise from reflex action. The general nervous irritability may be relieved by bromide of potassium, sodium, or ammonium. One gramme daily (15 grains) of either, in three doses, is well tolerated for a long period. When there are symptoms of an imminent convulsion, or to soothe the convulsibility which may break out any moment, chloral hydrate, eight or ten grains in from one hour to four hours, two grains in a dose, will be convenient. If the stomach refuses or is to be spared, from four to eight grains may be given in an enema of warm water. A severe attack of convulsions ought to be checked with inhalations of chloroform. When a warm bath is to be had, care should be taken that the child be not tossed about. Hold the baby in a small sheet or a large napkin, and immerge it thus into the water, raising the head and cooling it with cold cloths or an ice-bag. Genuine attacks of laryngismus with well-developed stages—the first paralytic, the second spasmodic—give but little time for any treatment. The proposition to apply the electrical current is well meant, but the attack has passed by, or terminated fatally, or resulted in a general convulsion, before the apparatus can possibly be in operation. I can imagine, however, that a Leyden flask kept ready might be used to advantage during the stage of apnoea for the purpose of bringing on inspiration. Sprinkling with cold water, beating with a wet towel, shaking by the shoulders, may certainly contribute to awake respiratory movements. The advice to wait quietly until the attack has passed by is more easily given than carried out. Marshall Hall's direction to perform tracheotomy will, I hope, soon be forgotten.

Nothing is more gratefully appreciated by the little patients than air. May it never be forgotten that night-air is better than foul air, and that furnace-air means air greatly modified by injurious additions. More than twenty years ago I was in occasional attendance upon a male baby—now a medical man of some promise—with craniotabes and a number of general convulsions. No treatment would remove, or even relieve, the attacks, until, without the physician's advice, the father took the baby into the street in the hardest winter weather. After the first long absence from his furnace the baby was well of his convulsions, and the physicians profited by their involuntary experience.

In the same way that salt-bathing is beneficial, so is sea-air. A summer at the seaside is a great blessing to rachitical children. Sea-baths have been arranged for them in France (Berx-sur-mer), in Italy (San Ilario di Nervi, Viarreggio, Livorno, Volti, Fano), in England (Margate), in Germany (German Sea, by Prof. Beneke), and for some little time past in the neighborhood of our own large cities.

Complications command great attention in rachitis, particularly where there is danger from the affection of the nerve-centres, for the slightest irritation in some distant part of the body may give rise to an outbreak. Thus, in craniotabes it is desirable to watch even the gums. Not sharing the etiological superstition which attributes so many diseases of infancy to dentition, I still know that a slight irritation of the gums may suffice to exhaust the slim resisting power of the infant. If there be local swelling and congestion of the gums over a growing tooth, it may become necessary, or at least advisable, to lance. An otitis which under ordinary circumstances would give rise to no symptoms at all besides some inconvenience or slight pain will prove the source of great danger in a rachitical (craniotabic) infant. The chronic bronchial catarrh and frequent broncho-pneumonia of such patients require early attention, for they and the neighboring lymphatic glands stand too much in the relation of a vicious circle of cause and effect.

Rachitical constipation, depending on incompetency of the intestinal muscle, must not be treated with purgative medicines. Now and then, when a great deal of abnormal acid is formed in the stomach, calcined magnesia, a grain or two given before each meal, will control that disorder and at the same time keep the bowels open. But, as a rule, every purgative after it has taken effect will leave the intestinal muscular layer less fitted to perform its functions than before. Its place may be taken by a daily enema of tepid water. Further indications are—such a change in the food as will contribute to keep the bowels moist and slippery, but principally such a modification of food and such medical treatment as are known to prove beneficial when all the symptoms of rachitis are fully developed. When the cause of the infant's rachitis can be traced back to the mother or to an insufficient quality of her milk, she must give way to a wet-nurse, or the nurse must be changed for similar reasons. When neither mother nor wet-nurse prove competent, or either be dangerous, artificial food will take their place to advantage in the manner I have stated above. Beef-soup or beef-peptone is to be added to the baby's food daily. Of the two best farinacea, barley- and oat-meal, the latter is preferable as an addition to cow's milk, because of its greatly laxative effect. The percentage of cow's milk in the food ought to be more carefully watched than in other conditions. Pure cow's milk or cow's milk mixed with water only is borne worse in no other condition. Half a drachm or more of table-salt and a few drachms of sugar ought to be added to the daily mess. The general indications require the administration of iron, which has no constipating effect in this ailment. Particularly is that the case with the iodide of iron. Cod-liver oil, in three half-teaspoonful or teaspoonful doses daily, acts very satisfactorily both for its general rachitical and for its local effect on the mucous membranes. Now and then massage, repeated many times a day a few minutes each time, practised with the palm of the hand only, or gentle friction, with the dry or oiled hand, of the abdominal surface, will prove effective in bringing about peristalsis and strengthening the intestinal muscle. An obstinate case may also require two daily doses of one one-hundred-and-fiftieth or one one-hundred-and-twentieth of a grain of strychnia for the same purpose, or such other improvements on the above detailed plan as the judgment of the attending physician may direct. At all events, the diagnosis of any case, and the appreciation of the cause of any ailment, are, to a well-balanced and educated mind, of infinitely greater value than any number of specified rules and prescriptions.²¹

²¹ Jour. Obstetr., Aug., 1869.

It is not impossible that phosphorus, in substance, not in any of its compounds, may prove of great utility in the treatment of rachitis. Minimal doses of phosphorus render the newly-formed tissue at the points of apposition of the bones more compact in a very brief time. The new formation of blood-vessels in the osteogenous tissue gets retarded by it. Larger doses of phosphorus, however, increase vascularization, and osseous tissue is either less rapidly formed or even softened. When the doses are still larger, vascularization and softening may rise to such a point as to separate the epiphysis from the diaphysis. Thus the administration of the drug results in an irritation which, according to the doses employed, may give rise either to normal condensation or to inflammatory disintegration. This experience, arrived at by Wegner in a great many experiments made on animals, Kassowitz has confirmed. For its therapeutic effect he tried phosphorus in 560 cases of rachitis. Employing doses of one-half milligramme (one one-hundred-and-twentieth of a grain) several times daily (less will suffice), he soon found the skull to become harder, the fontanel smaller, the softening of the bones of the thorax and extremities to disappear, and all the other symptoms of rachitis to improve. This result was obtained though no particular change in the feeding of the patients was resorted to. To what extent this experience will be verified by others we shall soon learn. My own is already sufficiently extensive to base upon it a strong recommendation of the plan of treatment I have detailed. My therapeutical results in other diseases of the bones also encourage me to believe that phosphorus will accomplish much in the treatment of rachitis. Ever since Wegner's publications—viz. these thirteen or fourteen years—I have utilized phosphorus in cases of chronic and subacute inflammations of the bones, mainly of the vertebral column and the ankle-joint and tarsus. After having taught the method for many years in my clinic and otherwise, I made a brief communication on the subject to the Medical Society of the State of New York.²² Since that time, again, I have followed the same plan in many cases of the same description, and feel sure that the prognosis in this serious class of bone diseases has become more favorable and recovery speedier. Infants of a year or more were given a dose of one-eightieth or one one-hundredth of a grain of phosphorus daily. One grain, dissolved in an ounce of oil or cod-liver oil, is a convenient mixture, four or six drops of which may be administered daily in two or three doses.

²² Trans., 1880.

From what I have seen of phosphorus in bone disease, and what is thus far known by experience in rachitis, it appears to me that it will be of decided advantage in that form of acute rachitis which is apt to destroy rapidly with the symptoms of acute epiphysitis, rapid pulse, diarrhoea, rapid diminution of strength, and scorbutic gum. In the few cases I have seen these last years it appeared to me to act satisfactorily, together with immobilization of the whole body.

Rachitical curvatures are very apt to become less marked while growth is increasing and the limbs extending. But many of them are so marked that they remain for life. Many of these might have been benefited by timely orthopædic interference. That the application of Sayre's jacket is indicated in every form and stage of spondylitis, though it be not equally valuable in all forms, goes without saying; and that infractions ought to be straightened and supported by splints when observed and when practicable, is self-evident. But, as a rule, while the chronic rachitical process is developing in the long bones the use of mechanical apparatuses is of doubtful merit; they ought not to be resorted to before the healing has at least commenced. Nor is it advisable to postpone mechanical interference so long that eburnation of the bones has time to take place. Surgical operations for the purpose of removing the curvature are of different nature according to the different types to be treated. Mere straightening of the curvatures is indicated, and successful with children under two years. Osteoklasy—that is, fracturing of the curvature while the periosteum is left intact—is successful in children of three (or four, according to Volkmann) years. The fracture does not injure the periosteum, and is always transverse. In later years osteotomy has proved successful to an almost unexpected degree, and is one of the happiest achievements of modern surgery.

Partly as a preventive, partly as a curative measure, Gramba of Turin and Pini of Milan point to well-directed gymnastics as a requisite in the treatment of rachitis. For older children they have established schools in which systematic exercises are brought to bear on chronic deformities.