Rickets, a disease peculiar to infants from the age of nine months, to the third year; and which seldom continues till they attain to puberty. Its principal symptoms are, a large head, a prominent forehead, a relaxed skin, and swelling of the belly. The joints acquire an unnatural size; the bones, especially those of the legs and arms, become curved; and the cartilages of the ribs being deprived of their elasticity, are unable to support the chest ; in consequence of which, it projects and grows deformed. In the progress of this malady, the belly is extremely tumid and hard to the touch, particularly on the right side; the teeth become black and carious ; and the general emaciation is such as to leave the patient almost inanimate, having power only to move the neck and head.

The proximate cause of the dis-order is now understood to be a de-ficiency of the phosphate of lime, or animal gluten in the bones : hence the latter are deprived of that necessary strength and solidity, in consequence of the prevailing debility in the vessels, so that the former, instead of being conveyed to the bones, is deposited in other parts of the body. Thus, we find particles of lime often evacuated by the urine, or sometimes lodged in the genitals.—See also Bones.

Among the pre-disposing causes, we shall briefly mention, the ne-glect of proper exercise, or what may be called had nursing ; frequent exposure to damp or mephi-tic air in close habitations ; an improper system of living, with re-spect to food and drink ; for instance, watery and mealy substances, particularly viscid pap, pastry, fish, salt-meat, and other articles, too difficult of digestion. Some-times, however, it arises from the vitiated habits of parents ; or is consequent on other diseases, such as small-pox, measles, etc.

Although the rickets do not, in general, prove fatal, when timely attended to, yet this affection is not unfrequently followed by a curvature, and even a decay of the bones, particularly those of the arms, legs, spine, etc.

In the cure of this malady, mild, opening, and strengthening medi cines have been found useful: of the former, we recommend small doses of ipecacuanha, to act as a gentle emetic; rhubarb and manna, with the addition of nutmeg, or fennel-seed. Among the safest astringents, are quassia, Peruvian bark, and calcined zinc, in very-small proportions, to be frequently repeated; but the cold bath, fresh air, and moderate exercise, are eminently beneficial. Iron filings, though considered a specific cure for this complaint, should be prescribed only by the faculty.

In the western isles of Scotland, the rickets are effectually cured by an oil, extracted from the liver of the skate-fish : with this intention, the wrists and ancles are rubbed with such oil in the evening, so that a fever of several hours duration is immediately excited. On the following evenings, the same operation is repeated, as long as the unction of those parts produces similar effects. When no febrile action can be induced by the friction of the wrists and aneles alone, they are then rubbed together with the knees and elbows; in consequence of which a new fever ensues ; and this practice is continued accordingly. Then, the spine and loins are to undergo the operation, together with the former parts, to re-produce the symptoms of fever ; and, when these likewise are no longer susceptible, a flannel shirt, dipped in the oil, is put upon the body of the patient ; by which expedient a fever more violent than from any of the preceding applications is roused, and this general covering is worn next the skin, till the cure is completed ; an event which generally takes place within a short time.—We have stated this heroic remedy, on the authority of

Dr. Duncan, sen. of Edinburgh ; who has inserted it in the 17th volume of his Medical Commen-t'aries: but we apprehend, that few English parents will be inclined to submit their infants to this febrile stimulation ; though we entertain no doubt of its efficacv, provided it be equally safe.