Science has always admitted, and values every day more highly, the importance of cleanliness around the patient and on the part of the physician; and things of different kinds have been used as disinfectants in many cases of disease. The healer, who has to do more with the mind, must, therefore, realize how very important it is to consider purity of mind as well as of body for the purpose. No doubt it is difficult after learning the nature of things to say which is pure and which is impure.