Tonsilitis lasts three days usually. The throat symptoms may take a day or two longer to clear up, and the patients feel more or less weak for some time after all the symptoms have disappeared. Tonsilitis is medically regarded as one of the mild diseases of childhood. It is, however, of very great importance because of its likeness to diphtheria, and inasmuch as a positive diagnosis must be promptly made, in the interest of the patient, it is given close attention and treated with considerable respect by the medical profession. The chief differences between the two diseases are as follows: Tonsilitis begins abruptly with pronounced prostration and a high fever the first day. The patient feels distinctly sick all over. The second day the patient feels somewhat better, the fever is lower and the prostration and pain are not so marked. The third day he feels better still, and but for a little weakness would feel well. Diphtheria begins slowly and insidiously, with very little prostration and a very low fever the first day. The patient scarcely feels sick. The second day more prostration is present, the fever climbs upward a little more, and the patient begins to feel sick. On the third day the prostration is much more profound, the fever is higher, and all the evidences of a serious sickness are present. Two very different pictures: The one begins bad and ends easy, the other begins easy and may end bad. The important fact, however, so far as the similarity of the two diseases is concerned, is, that we must make the diagnosis positive on the first or second day, because if we are dealing with a case of diphtheria we must give antitoxin at once. This is essential, because the efficacy of antitoxin is greatest when given early in the disease. By "early" we mean the first or second day of the disease. When antitoxin is given late (the third or fourth day of the disease) it is much less efficacious and must be given in relatively larger doses. The need, therefore, of a quick, positive diagnosis is a real one. Another important element involved in a speedy diagnosis is, that we must not take any chances of infecting other children. So important are these conditions that it is the proper treatment to give antitoxin at once in every case of tonsilitis that in the slightest way resembles diphtheria. An examination of the throat contents,--a culture of which is taken during the first visit of the physician,--will, of course, reveal the true condition and dictate the future use of the antitoxin. Antitoxin is absolutely harmless when given to a patient who has no diphtheria. Every case of tonsilitis should be quarantined when there are other children in the house.