careless mingling with friends and neighbors when at the beginning or end of an attack of communicable disease. The isolation of even frank cases of the so-called mild diseases is still too often regarded as an unreasonable imposition by the uneducated (and the uneducated are by no means always those of the most limited incomes). We still hear "Every one must have measles and the children might as well have it as soon as possible." There has seldom been a more cruel superstitution. The children's diseases, measles, scarlet fever and whooping cough are no light matter. Each one of them kills more victims than smallpox, and in many cities often more than typhoid fever. In New York City in 1912, there were two deaths from smallpox, 500 from typhoid, 671 from measles, 614 from scarlet fever and 187 from whooping cough. Furthermore, the seriousness of these maladies decreases directly with the age of a child, so that each year for which an attack may be postponed is so much gained. With the progress of health education in the public schools we may look for the day when the social crime of spreading communicable disease will be realized at its full value, so that it will be recognized as wanton recklessness, not courage, to continue business or social intercourse when "coming down," half-sick with some as yet undefined but impending disease, and no thoughtful person will hasten to mix with his fellows when possibly still a carrier after an attack. In all these diseases there are two factors, the invading germ and the more or less susceptible host, and even a common cold is often due less to poor vitality than to fresh and virulent infection. Some day, perhaps, responsibility may be felt for the reckless dissemination of even this supposedly mild disease, of which Dr. Rosenau well says in his recent work on "Preventive Medicine and Hygiene": "Could the sum total of suffering, inconvenience, sequelæ and economic loss resulting from common colds be obtained, it would at once promote these infections from the trivial into the rank of the serious diseases."
It is of course, not essential that "isolation" of an infected person should mean solitary incarceration within four walls. In the Middle Ages the only protection against disease was quarantine, which in its derivative meaning was forty days' detention of all persons, well or sick. coming from an infected port. With the progress of sanitary science preventive measures have become at the same time more efficient and less irksome. When ships from cholera countries came to our eastern seaports two years ago, only a detention of a day or so was necessary, pending a bacteriological examination of the passengers and detection of the few carriers among them. Isolation of individuals takes the place of quarantine against nations, and a practical isolation may often be effected by simple precautions against the transfer of discharges, without interference with human intercourse. Disease germs do not fly across a room to seize on their prey. They are carried by direct material contact of some sort, by the discharge of mouth spray, by hand
