The most critical period in the life of an infant is that of dentition or teething, especially at the early stages. An adult has thirty-two teeth, but young children have only twenty, which gradually loosen and are followed by the permanent teeth. When the child has ten teeth on each jaw, all that are added are the permanent set, which should be carefully preserved; this caution is needful, as sometimes decay in the first double teeth of the second set are supposed to be of the transient set, and are so neglected, or are removed instead of being preserved by plugging. When the first teeth rise so as to press against the gums, there is always more or less inflammation, causing nervous fretfulness, and the impulse to put everything into the mouth. Usually there is disturbed sleep, a slight fever, and greater flow of saliva; this is often relieved by letting the child have ice to bite, tied in a rag. Sometimes the disorder of the mouth extends to the whole system. In difficult teething, one symptom is the jerking back of the head when taking the breath, as if in pain, owing to the extreme soreness of the gums. This is, in extreme cases, attended with increased saliva and a gummy secretion in the corners of the eyes, itching of the nose, redness of cheeks, rash, convulsive twitching of lips and the muscles generally, fever, constipation, and sometimes by a diarrhea, which last is favorable if slight; difficulty of breathing, dilation of the pupils of the eyes, restless motion and moaning; and finally, if not relieved, convulsions and death. The most effective relief is gained by lancing the gums. Every woman, and especially every mother, should know the time and order in which the infant teeth come, and, when any of the above symptoms appear, should examine the mouth, and if a gum is swollen and inflamed, should either have a physician lance it, or if this can not be done, should perform the operation herself. A sharp pen-knife and steady hand making incision to touch the rising tooth will cause no more pain than a simple scratch of the gum, and usually will give speedy relief. The temporary teeth should not be removed until the new ones appear, as it injures the jaw and coming teeth; but as soon as a new tooth is seen pressing upward, the temporary tooth should be removed, or the new tooth will come out of its proper place. If there is not room where the new tooth appears, the next temporary tooth must be taken out. Great mischief has been done by removing the first teeth before the second appear, thus making a contraction of the jaw.