_Mode of Infection._--The germs of diphtheria may be carried in articles used by persons with the disease, or they may be communicated by direct contact. The micro-organism is found in the secretions from the mouth, throat, or nose, and in particles of detached membrane. Bedding, utensils, etc., used in the room where a patient has diphtheria, are liable to carry the germs if taken from the sick-room, and consequently should be always properly disinfected before being removed. Milk-bottles carried into the sick-room, or handled by persons caring for the patient, should never be returned to the dealer without being disinfected. Cats, and less frequently dogs, may contract the disease and convey it to those with whom they come in contact. Unrecognized mild cases are a frequent means of spreading the disease, as also is a too early release of patients after recovery. It is a much safer method of procedure to require at least two negative examinations before releasing a patient from quarantine, as during convalescence the germs may be entirely absent on one day and a few days later be quite abundant. The bacilli may remain in the throat from a few days to several years after the disease is apparently entirely well, and under such circumstances the persons carrying them become quite as great, if not a greater, menace to those with whom they came in contact as they were during the height of the disease. A thorough disinfection of the room and everything used about the sick person should be carried out after the patient is released. Complete isolation should be observed during the illness, and as long as the bacilli remains in the throat.