The breathing of a child in health is formed of equal inspirations and expirations, and it breathes quietly, regularly, inaudibly, and without effort. But let inflammation of the air-tubes or lungs take place, and the inspiration will become in a few hours so quickened and hurried, and perhaps audible, that the attention has only to be directed to the circumstance to be at once perceived. Now all changes which occur in the breathing from its healthy standard, however slight the shades of difference may be, it is most important should be noticed early. For many of the complaints in the chest, although very formidable in their character, if only seen early by the medical man, may be arrested in their progress; but otherwise, may be beyond the control of art. A parent, therefore, should make herself familiar with the breathing of her child in health, and she will readily mark any change which may arise. Of cough I should not have said any thing in this chapter, as it can never fail to be noticed, except that it is highly necessary to throw out one caution. Whenever a child has the symptoms of a common cold, attended by hoarseness and a rough cough, always look upon it with suspicion, and never neglect seeking a medical opinion. Hoarseness does not usually attend a common cold in the child, and these symptoms may be premonitory of an attack of "croup;" a disease excessively rapid in its progress, and which, from the importance of the parts affected, carrying on, as they do, a function indispensably necessary to life, requires the most prompt and decided treatment.