A constant period of incubation is not to be expected. In most instances, as will be seen from the following table, the difference between the maximum and the minimum period is not very great. It seems remarkable, however, that a disease should show such extremes as typhoid fever: Normal. Maximum. Minimum. Variola 12 days. 14 days. 9 days. Varicella 14 “ 19 “ 13 “ Measles 10 “ 14 “ 4 “ Rubella 18 “ 21 “ 8 “ Scarlatina 2 “ 7 “ 1 day. Influenza 3 “ 5 “ 1 “ Diphtheria 2 “ 7 “ 2 days. Typhoid fever 12 “ 23 “ 5 “ Mumps 19 “ 25 “ 12 “ It is a peculiar fact that the diseases in which the period of incubation is shortest are those in which the infection persists the longest. The period of quarantine must be guided largely by the period of incubation, hence the subject is an important one for a variety of reasons. The “Medical Magazine” (London) states that the period of quarantine should be at least a day longer than the maximum period of incubation for each disease. This is a very uncertain rule, however, for the patient should be free from all signs of illness, and especially from fever. The period of infection is very doubtful. It may be greatly prolonged by complications. This is especially true of small-pox, diphtheria, typhoid and scarlet fevers. The period during which a disease may be infectious cannot be stated definitely. It varies with different diseases, and must be determined according to the symptoms and character of the case. Measles, chicken-pox, and mumps lose the direct power of infection very early, and the infective principle does not remain active for a long period in the room in which the patient has been ill. Measles, mumps, and chicken-pox may be infectious in the earlier stages before becoming definite in character. Smallpox is not actually dangerous until the eruption appears. THE CARE OF THE SKIN AND MOUTH IN FEVERS. BY HARRIET HIGBEE, Graduate Illinois Training School for Nurses. _From the American Journal of Nursing._