This book is writen in about medical science. and toxin or position produced by the hostile germs and render it entirely harmless. By a curious paradox of the process, it does not kill the germs themselves. Now, where and how did nature ever succeed in getting the rehearsal and the practice necessary to build up such an extraordinary and complicated system of defense as this? Take your microscope and look at a drop of fluid from the mouth, the gums, the throat, the stomach, the bowels, and you will find it simply swarming with bacteria, bacilli, and cocci, each spe.