RICKETS, or Rachitis (from ifelyets, the spine), is a disease in which the bones being of unnatural softness, some of them bend under the weight of the superincumbent parts of the body. Bones affected with rickets present such a softness of texture that they may be cut with a knife; their walla are remarkably thin, and their interior, instead of being filled with marrow in their bony cells, is occupied by a semi-fluid jelly-like substance of a reddish colour, which fills a number of rounded cavities of irregular size. The quantity of earthy matter in such bone. is reduced to considerably lees than its natural proportion, and they lose much of their normal weight. All the bones may be thus affected, but it is only those which have to bear the weight of the body that give evidence of it by bending; the arms, for example, never change their form, but the thighs and legs become arched forwards under the weight of the trunk ; the spine assumes a variety of curves from the pressure of the head ; the breast-bone becomes prominent, and the ribs flattened; the haunch-bones grow outwards, and the pelvis is sometimes seriously deformed by an approximation of its anterior and posterior boundaries.
Rickets', as far as the softness of the bones is concerned, cannot be regarded as a dangerous disease ; for this condition is generally re covered from, though not without deformity of the tank and lower limbs. But the disease of the bones is commonly only a part of a general state of disease affecting many other organs of the body. The muscles; are always pale and weak, and there are all the signs of general debihty; and besides these, the brain and the organs contained in the chest and abdomen are peculiarly apt to suffer, and become the seat of fatal diseases, such as hydrocephalus, phthisia, obstruction of tho mesenteric glands, &a.
The general symptoms present iu cases of rickets are so much like scrofula. that many writers treat rickets but as one of the many forma in which scroful.? priaents itself. (Senoeeta.) At any rate, in the treatment of rickets tho same general plan is found to be equally eilimcious. The causes of rickets are to be *ought in an improper diet, and exposure to those conditions of life which prevent a duo oxidation of the blood, and an imperfect assimilation of the food. It is more frequent In children living in large towns, or overcrowded villages, than ausonget therm who obtain healthy food and pure air. One of the most important elements of treatment is the removal of the patient from any overcrowded district in which it has been living into the country, where it can have pure air, and if ponsible sea air. In young children,
fresh cow's milk, with baked wheaten flour, and meat teas, should be administered. Cosl-liver oil should be given as medicine, and cream may be added to the cow's milk, and butter may be freely taken with the food. The deficiency of phosphate of limo may be repaired by the administration of jellies made from ivory or bone dust, which may be made palatable with spices and sugar.
When rickets affects only or chiefly the bones, an attention to the means just mentioned will, with advancing age, usually load to a ter mination of the disease. The bones will gradually become hard by the addition of their natural quantity of earthy matter. They retain indeed the curves which they acquired in their condition of softness, but the want of strength which might result from this change of form Is compensated by the remarkable thickness and strength which they aoluire in the concavities of- the curves, upon which the chief atress from the freight of the body falls.
Young persons are exclusively subject to rickets. It occurs at the ago of two or three years, and from that time to puberty, and as the curvatures begin to form as soon as the weight of the body is thrown on the limbs by aasuming the erect posture, it is commonly proposed to support the upper part of the body and the limbs by irons. Such messurea hoc-ever are. in a large majority of cases, full of mischief ; if they can ever accomplish their intention of supporting the head and trunk, it can only be by preventing entirely that active use of the limbs which is essential to the attainment of the proper hardness of the bones. It is constantly observed that the strength and density of bones are in direct proportion to the habitual exertion of the muselee attached to them ; and as the latter are -made inactive by irons, the application of any such modes of restraint cannot but be injurious to those affected with rickets.
When children first begin to walk, their legs not unfrequently become a little bent. This is especially the case with those that are large, and have heavy bodies to bear ; but it is not to be regarded na sign of rickets, and when the muscles of the limbs become stronger, and the bones in their natural process of development grow harder, the curvatures will gradually disappear. The distinction between this kind of bending of the legs and that dependent on rickets may be made by the condition of the general health in each ; in the former it Is unaffected, or may even be more than usually good, in the latter it is always weak and disordered.