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.