=Incontinence of Urine.=--The irritation which this mechanical inconvenience produces sometimes has to do with that troublesome infirmity of some children, who wet the bed at night. This may also be induced by a very acid, and consequently irritating, state of urine, either with or without the appearance in it of gravel. Often, however, it is a result of want of care on the part of the nurse, who neglects to cultivate regular habits in a child; and does not pay attention to the quantity of liquid taken at its last meal. Something, too, is due to the fact that the sleep of a child is deeper than that of the grown person, so that the sensation of want, which would arouse the latter to full consciousness, does not have the same effect on the former. It sometimes happens undoubtedly from mere indolence; and this may always be suspected when a child, otherwise healthy, wets itself not at night only, but also in the daytime. Lastly, it does sometimes occur from muscular feebleness in weakly children, the bladder being unable to bear more than a limited degree of distension. The accident usually happens either soon after going to bed, when the warmth stimulates the action of the bladder, or towards morning, when the bladder has become full. The posture on the back favours its occurrence very much, and it is therefore of importance that the child should lie on its side when in bed. The good effect of a blister on the lower part of the back as a means of cure was largely due to its forcing the child to lie on its side. This object can be attained, however, in a much kindlier way, by tying half a dozen cotton reels together, and fastening them at the child's back. The habit may also often be broken through by arousing the child in the night, and compelling it to empty its bladder, the hour being first ascertained at which the accident usually happens. For this, however, to be of any real use, the child must be awakened thoroughly; since otherwise it will mechanically, and quite unconsciously, empty its bladder while still asleep. The habit in this case is not in the least overcome; only for the time the bed escapes the wetting. The utensil must therefore be placed on different nights at different parts of the room, so that the child, in order to find it, must have been roused to thorough consciousness. Lastly, I will add that the cases in which the accident is the result of mere indolence are very rare, and though in such cases strictness may be necessary, yet actual punishment is out of place. As a rule, reward answers much better. A penny, or a threepenny-piece every night that the accident does not happen, and a forfeit of a halfpenny or two pence for every night of misfortune, is a very efficacious help to a cure. When all these domestic means, persevered in for months, fail to produce any result, medical aid must be called in. CHAPTER IX. CONSTITUTIONAL DISEASES.