"A Parisienne allowed herself to be kissed by a clean-shaven and then by a bearded man. After each salute her mouth was stroked with a sterilized brush. The microbes thus collected were deposited in a test tube and allowed to incubate for four days. It was shown that the clean-shaven man had deposited a small quantity of harmless particles. His rival's kiss had colonized the lady's lips with the bacilli of tuberculousis, diptheria, pneumonia, and numerous other unpleasant microbes."
Facial hair can harbor some nasty shit, yo. Scrub those beards!