Mankind has been the subject to infection by microorganisms since before the dawn of recorded history. One presumes that mankind has been searching for suitable therapy for nearly as long. This was a desperately difficult enterprise given the acute nature of most infections and the nearly total lack of understanding of their origins prevalent until the last century. The chronicle of civilization before the discovery of bacteria and their role in infectious disease and, subsequently, of the discovery of antibiotics and antimicrobial agents is punctuated by the outbreak of recurrent devastating pandemics. An example is the successive waves of bubonic plague which dramatically decreased the population of Europe in the middle Ages. Mankind was mystified as to the cause of infectious disease and what one must constructively do for prevention and cure. In warfare, infections often disabled or killed more individuals than did the action of generals. Our own family histories record the premature loss of loved ones, particularly small children, to one infection or another and in the third world this pattern is all too common today.