Invisible in the atmosphere and found on dust, in water, in all foods, and contaminating every physical substance on earth, there are millions of pathogenic organisms that cause suffering and sickness in the human body. These tiny creatures called germs or bacteria, are so microscopic the human eye cannot see them unless they are magnified in the lens of a high-powered microscope. It is impossible that any human being could have known of the presence of these disease causing organisms until Louis Pasteur proved their reality in the last few hundred years. It is interesting to note that everyone of science in his day opposed his ideas when they emerged, and it was many years before his information was accepted.
But now that we know of their existence, and have the science of Bacteriology that studies their nature, structure, substance and organization, doctors make a fetish of washing and sterilizing. You have no doubt seen surgeons preparing to enter the Operating Theater. The first stage in the preparation, after they have gowned themselves in a white or green robe and covered their hair with a surgical cap, is to spend time washing their hands from fingertips to elbows with hot water and special detergents, until their hands are as sterile as they can be. These clean hands are then wrapped in a sterile towel so they may not be contaminated by the air, and the nurse binds over the doctor’s mouth and nose a sterile gauze pad.
Many of these Pathogens ride on the human breath. They cannot pass through the layers of gauze in the face mask, and are trapped and rendered innocuous.