There still seems to be some who do not recognize the difference between a " Lister dressing" and "Listerian principles." It does not seem sufficient to say that the dressings may change but the principles cannot, as this has been repeatedly pointed out during the past four years, or more. Nor does it seem sufficient to say that all the principles of aseptic and antiseptic surgery and medicine are comprehended in the one word " cleanliness," as this has been repeatedly done, even by Sir Joseph Lister himself. Again, there are many who, seemingly, cannot understand the value of circumstantial evidence in medicine; they insist upon proof—absolute and incontrovertible, and question the pathogenic influence of dirt and germs in much the same way that the Rev. John Jasper disputes the movement of the earth about the sun. Those who, without any special knowledge of bacteriology and the etiology of disease, insist upon