Health officers now watch like hawks for the appearance of any case of typhoid among or in the families of dairymen. The New York City Board of Health, for instance, requires the weekly filing of a certificate from the family physician of all dairymen that no such cases exist. And the more intelligent dairymen keep a vigilant eye upon any appearance of illness accompanied by fever among their employees, some that I have known even keeping a fever thermometer in the barn for the purpose of testing every suspicious case. How effective such precautions can be made may be illustrated by the fact that, in the past five years, there has not been a single epidemic of typhoid traceable to milk in Greater New York, even with its inadequate corps of ten inspectors, and the six states they have to cover. The moment a single case of typhoid appears, the dairy or milkman supplying that customer is given a most rigid special inspection, and, if any source of infection can be discovered, the milk is shut out of New York City until the department is satisfied that all danger has been removed. One or two lessons of this sort are enough for a whole county of dairymen. The danger of transmission of typhoid through milk has been enormously exaggerated, and, as in the case of all other milk-borne diseases, is entirely due to filthy handling, and may be prevented by intelligent sanitary policing. Even with our present exceedingly imperfect systems, probably not more than between five and ten per cent of typhoid is transmitted in this way; and, if the water-supply were kept clean, this would practically disappear. Typhoid may not only be transmitted from the earth beneath and the water under the earth, but also from the heavens above, through the medium of flies and dust. The first method is bulking larger every day, especially in country districts and in camps. The _modus operandi_ is simplicity itself. The fly lives and moves and has its being in dirt. It breeds in dirt and it feeds on food, and, as it never wipes its feet, the interesting results can be imagined. Just to dispel any possible doubt, plates of gelatine have been exposed where flies could walk on them, then placed in an incubator, and within forty-eight hours there was a clearly recorded track of the footprints of the flies written in clumps of bacilli sown by their filthy feet. More definitely, flies have been caught in the houses of typhoid patients, put under the microscope, and their feet, stomachs, and specks found swarming with typhoid bacilli. A single flyspeck may contain three thousand.