The subject of disinfection is so broad and covers such a wide range of considerations that it is impossible to discuss it properly in the brief time allowed for this paper. Important as are such subjects as the disinfection of the patient's body, instruments, dressings, discharges of various kinds, etc., I have deemed it more important to view and consider the subject from the broader standpoint, namely, the disinfection of premises following contagious diseases. For the disinfection of premises following contagious diseases a great many substances might be used. It may safely be said, I believe, that nine out of every ten of the advertised disinfectants are of very little value. Some of them are of some value as antiseptics and deodorants. Many of these advertisements are accompanied by good testimonials. There are three agencies that we should always keep in mind in general disinfection: 1, A gaseous disinfectant; 2,