Bacteriphobia.--The development of bacteriology has had a similar effect, especially because periodicals and newspapers like to take up only the sensational side of biological discoveries. Most physicians who have had anything to do with nervous diseases have seen cases of misophobia, the fear of dirt, which in our day has taken on the special character of fear of microbes. Those who are sensitive to the possibility of contamination learn of the almost sacrificial precautions that surgeons take to avoid wound infection, and conclude that practically everything they handle must fairly reek with microbes. They hesitate about touching the door knob or latch, and invent all sorts of excuses to wait for a moment outside the door in order to have someone else open it. Especially are they timorous about touching the door knobs of a physician's residence, or the chairs in his waiting room, or even to shake hands with him. Hospital walls and doors become an abomination to them. These cases emphasize how much of unfavorable suggestion there has been in the present spread of popular knowledge with regard to microbes. A writer on popular science once said that every time we spread a piece of bread of the size of the hand with butter, we scatter over its surface as many microbes as there are inhabitants in the United States. The expression has gone the rounds, producing its effect on sensitive people, occasionally causing even a disgust for so important an article of diet as butter, more often giving rise to an extreme sensitiveness with regard to any special savor that butter may have, and it may have many according to the prevailing food of the cow. There has been much emphasis laid on the potentialities for harm of the microbes, and very little on the important part which they play in the production of many forms of food materials. Most people know and dread the fact that microbes produce disease. Very few seem to realize that while we know many thousands of different kinds of microbes, scarcely more than a score of them are known to be seriously pathogenic, while all the others are either indifferent or, as we know of very many, are actually benefactors of mankind.