Time and again measles has been widely diffused on Asiatic and European soil, and shortly after the colonization of America it appeared in our colonies. Many are the quaint records of its visitations, not the least interesting of which is a letter which appeared in the Boston Evening Post, November 12, 1739, entitled "A letter about good management under the distemper of measles at this time spreading in the country, here published for the benefit of the poor and such as may want help of able physicians." It is signed "Your hearty friend and servant," and the authorship is attributed to Cotton Mather. It is stated that this letter is a reprint of one which Dr. Mather wrote prior to his death in 1728. At present the disease is distributed over the entire habitable globe, from Iceland on the north to Tierra del Fuego on the south. It occurs most often and more severely in the colder months, probably because at such times people are more closely crowded together under more insanitary conditions. When introduced among a people who have never suffered from it before, its ravages are frightful, as in the case of the inhabitants of certain of the Fiji Islands, who, upon being exposed to the infection, fell ill and died by thousands, so that it is estimated that 20,000 deaths occurred in four months. The epidemic ceased only when almost every person on the island had been infected. During the year 1910 the death rates from this disease in the States of Rhode Island and North Carolina were 32.6 and 27.1 per 100,000 inhabitants. In the same year the death rate per 100,000 from measles in Pittsburgh, Pa., was 33.1; Providence, R. I., 31.9; Kansas City, Mo., 28.4; Lowell, Mass., 28.1; Albany, N. Y., 23.9; Columbus, Ohio, 23.6; Buffalo, N. Y., 22.1; and Richmond, Va., 21.1. The death rate among those attacked varies from 1/2 to 35 per cent. If it is estimated that the death rate is 1 per cent, and the number of deaths from it in the United States during the year 1910 was 11,000, then it would follow that during that year at least 1,100,000 children suffered from this disease. When it is considered that perhaps 30 per cent of these children were of school age, and that the disease occurs most often during the months of school attendance, then it will be seen that 330,000 children were kept from school from six weeks to two months on account of measles. Leaving out of consideration the death and suffering which was produced in this way, this is a serious economic loss.