Moreover, we and our intelligences are a product of nature and a part of her remedial powers. So there is nothing in the slightest degree irrational or inconsistent in our attempting to assist in the process. However, a great, broad, consoling and fundamental fact remains: that in a vast majority of diseases which attack humanity, under ninety per cent of the unfavorable influences which affect us, nature will effect a cure if not too much interfered with. As the old proverb has it, "A man at forty is either a fool or a physician"; and nature is a good deal over forty and has never been accused of lacking intelligence. In the first place, nature must have acquired a fair knowledge of practical medicine, or at least a good working basis for it, from the fact that the body, in the natural processes of growth and activity, is perpetually manufacturing poisons for its own tissues. In this age of sanitary reform, we are painfully aware that the most frequent causes of human disease are the accumulations about us of the waste products of our own kitchens, barns, and factories. The "bad air" which we hear so frequently and justly denounced as a cause of disease, is air which we have ourselves polluted. This same process has been going on within the body for millions of years. No sooner did three or four cells begin to cling together, to form an organism, a body, than the waste products of the cells in the interior of the group began to form a source of danger for the others. If some means of getting rid of these could not be devised, the group would destroy itself, and the experiment of cooeperation, of colony-formation, of organization in fact, would be a failure. Hence, at a very early period we find the development of the rudiments of systems of body-sewerage, providing for the escape of waste poisons through the food-tube, through the kidneys, through the gills and lungs, through the sweat glands of the skin. So that when the body is confronted by actual disease, it has all ready to its hand a remarkably effective and resourceful system of sanitary appliances--sewer-flushing, garbage-burning, filtration. In fact, this is precisely what it does when attacked by poisons from without: it neutralizes and eliminates them by the same methods which it has been practicing for millions of years against poisons from within.