CALOMEL.--This medicine, as it is frequently given, alone, or in the little white powders, in infancy and childhood, by mothers and nurses, is productive of serious and indeed irremediable injury to the teeth. "The immoderate use of mercury in early infancy produces, more perhaps than any other similar cause, that universal tendency to decay, which, in many instances, destroys almost every tooth at an early age. It is certainly not unimportant to bear this fact in mind, in the administration of this sovereign remedy, this panacea, as many appear to consider it, in infantile diseases."[FN#26] [FN#26] Bell on the Teeth. HEAT AND COLD.--The teeth are exceedingly apt to suffer from sudden variations of temperature. Fluids, therefore, should never be taken into the mouth so hot or so cold as to produce the slightest pain; and, for the same reason, the water with which the mouth is cleansed should in winter be always warm or tepid. When ices are taken, the precaution of placing them in the centre of the mouth, so as to prevent contact with the teeth, should be carefully observed. There are many other causes which might be mentioned as tending to induce decay of the teeth, but their consideration here is purposely avoided. It is hoped that enough has been said to draw the parent's attention to the subject of the teeth, to prevent their neglect, and yet at the same time to induce a cautious management. CHAP. IV. HINTS FOR THE EARLY DETECTION OF DISEASE IN THE CHILD BY THE MOTHER. Life is soon extinguished in infancy. At this epoch any disease is formidable, and must be met most promptly. It is either sudden and active in its assaults, or comes with slow and insidious approach. The first signs of its coming on are not always visible to an unpractised eye: it may have made dangerous advances before the mother's mind is awakened to its presence; and medical aid may be solicited when remedies and advice are no longer of any avail. It is therefore highly important that a mother should possess such information as will enable her to detect disease at its first appearance, and thus insure for her child timely medical assistance. This knowledge it will not be difficult for her to obtain. She has only to bear in mind what are the indications which constitute health, and she will at once see that all deviations from it must denote the presence of disorder, if not of actual disease. With these changes she must to a certain extent make herself acquainted. Sect. I.--SIGNS OF HEALTH. The signs of health are to be found, first, in the healthy performance of the various functions of the body; the regular demands made for its supply, neither in excess or deficiency; and a similar regularity in its excretions both in quantity and appearance.