As the simple suggestion of the Prime Minister, that cleanliness of the home and its surroundings was the best measure of protection against cholera, contained the germ of practical sanitary reform in England, so an incident in the writer’s experience became the potential force that gave to New York a most complete system of health laws and ordinances, and an efficient administrative department of health. In a larger sense it may, with justice, be claimed that this incident contained the germ of health reform that has given to this entire country the most perfect system of municipal, state, and national health administration in the civilized world. The incident referred to occurred in the fifties of the last century. New York was in the grip of the deadly typhus. This was sometimes called the “Spotted Fever,” from the dark spots which appeared on the body of its victims, and also “Emigrant Fever,” because it was brought to this country by the immigrants, especially by those who came from Ireland. Indeed, the Irish immigrants suffered so generally and severely that the disease was sometimes called the “Irish Fever.” Immigration from Ireland was at that time at its flood and the typhus was so prevalent among these poverty-stricken people that the hospitals were overcrowded by them and large numbers were treated in tents, both on Blackwell’s Island and at the quarantine grounds on Staten Island. Having completed a two years’ term of service on the interne medical staff of Bellevue Hospital, where large numbers of typhus cases were treated, I was placed in charge of the tents on Blackwell’s Island by the Commissioner of Charities. Soon after entering upon the service, I noticed that patients were continually admitted from a single building in East Twenty-second Street. [Sidenote: A Fever Nest] Impressed with the importance of closing this fever-nest, I visited the tenement and was not surprised at the large number of cases of fever which it furnished our hospital. It is difficult to describe the scene that the interior of the house presented to the visitor. The building was in an extreme state of dilapidation generally; the doors and windows were broken; the cellar was partly filled with filthy sewage; the floors were littered with decomposing straw, which the occupants used for bedding; every available place, from cellar to garret, was crowded with immigrants--men, women, and children. The whole establishment was reeking with filth, and the atmosphere was heavy with the sickening odor of the deadly typhus, which reigned supreme in every room.