| Diseases. | Incubation lasts— | Date of characteristic symptom from beginning of invasion. | Characteristic symptom. | Other principal symptoms. | Whole duration of disease from onset. | Quarantine lasts from onset. |
| Typhoid fever. | 7 to 10 days. | 7th or 8th day. | Rose-red, slightly elevated spots. | Apathy; diarrhœa; nosebleed; headache. | 2 to 4 weeks. | While disease lasts. |
| Scarlet fever. | 1 to 7 days. | 1st or 2d day. | Intense, bright-red blush over body. | Sore throat; often vomiting with onset. | 7 to 9 days or more (not including desquamation). | 6 weeks. |
| Measles. | 10 to 11 days. | 4th day. | Dusky or purplish-red, slightly elevated spots, scattered and in characteristic groupings. | Cold in head; running eyes; cough; hoarseness. | 7 to 8 days. | 3 weeks. |
| German measles. | 7 to 21 days. | 1st day. | Pale, rose-red spots or uniform blush; no characteristic groupings. | Slight sore throat; sometimes slight running of eyes and nose. | 3 to 4 days. | 3 weeks. |
| Chicken-pox. | 13 to 17 days. | 1st day. | Pea-sized, scattered vesicles. | None; or slight fever. | A week or less. | 3 to 4 weeks. |
| Varioloid (Variola). | 7 to 12 days. | 3d day (may be 1st or 2d). | Red, elevated papules; then vesicles; then often pustules. | Headache; backache; vomiting. | About 14 days. | 4 to 8 weeks. |
| Varioloid (Variola). | 7 to 12 days. | 3d day (may be 1st or 2d). | Red, elevated papules; then vesicles; then often pustules. | Headache; backache; vomiting. | About 14 days. | 4 to 8 weeks. |
| Vaccinia (Vaccination). | 1 to 3 days. | 1st day (3d after vaccination). | A red papule, becoming a vesicle and then a pustule; surrounded by a broad red area. | Often feverishness and malaise. | About 3 weeks. | None. |
| Erysipelas. | 3 to 7 days. | 1st or 2d day. | Bright-red blush; puffy skin; often vesicles. | Fever; pain. | 4 to 6 days, or several weeks if it spreads. | Averages 2 weeks. |
| Diphtheria. | 2 to 12 days. | 1st or 2d day. | White membrane on tonsils and other parts of throat. | Debility; fever. | 10 to 14 days. | 3 to 4 weeks. |
| Whooping-cough. | 2 to 7 days. | 7th to 14th day. | A prolonged paroxysm of coughing followed by a crowing inspiration (whoop). | Vomiting; spitting of blood. | 6 to 8 weeks. | 6 to 8 weeks (while whoop lasts). |
| Mumps. | 7 to 21 days. | 1st day. | Swelling in front, below, and behind the ear and below the jaw. | Pain when chewing. | A week or less. | 3 to 4 weeks. |
| Influenza. | Uncertain. Probably 1 to 7 days. | 1st day. | Fever, prostration. | Various respiratory, digestive, or nervous symptoms, commonest being general aching and cough. | 3 or 4 days to two weeks or more. | While disease lasts. |