But the auto-infection that results from the absorption of the liquid waste into the blood supply is by far the most serious feature. The blood is the life. From it the system obtains all the material for the formation of fresh tissue, and it is a practical impossibility for good, healthy structures to be built up from a tainted blood current. Why is it that the vegetation on the banks of a stream, on which a manufacturing town is located, is invariably stunted and withered? Because the water that should nourish it is polluted by the refuse poured into it, and no amount of deodorants or disinfectants will prove of any avail to restore the devitalized vegetation, but will rather aggravate the trouble. But cut off the source of pollution, and in an incredibly short space of time the vegetation will take on a new lease of life. This liquid refuse in the colon is composed of substances for which the system has no further use--it has rejected them; consequently they are foreign bodies, and as such, are the equivalent of poisons. The colon, in this condition, is a perfect hot-bed for the breeding of all kinds of poisonous germs, and the action of cathartics aggravates the condition by filling the pouched portions of the colon with a foul liquid which facilitates the absorption of the ptomaines and leucomaines through the mucous coat of the intestine. It is known now, that as much as three-fourths of this foul putrid substance may be absorbed, carrying into the system poisonous germs and excrementitious matter. Dr. Murchison states, “that a circulation is constantly taking place between the fluid contents of the bowel and the blood, the existence of which, till within the last few years, was quite unknown, and which even now is too little heeded.” And Dr. Parker says, “It is now known, that in varying degrees there is a constant transit of fluid from the blood into the alimentary canal, and as rapid absorption.” It is also stated on reliable authority, “_that every portion of the blood may, and possibly does, pass several times into the alimentary canal in twenty-four hours_.” Prof. I. I. Metchnikoff recently stated in a lecture at Paris: “Particularly injurious are the microbes of the large intestines. Thence, they penetrate into the blood and impair it alike by their presence and the products they yield--ptomaines, alkaloids, etc. The auto intoxication of the organism and poisoning through microbes is an established fact.” Having shown that the average colon is a fertile breeding ground for all kinds of poisonous germs, and that they are conveyed into the circulation by the interchange of fluids in that organ, it may be interesting to explain how these germs are conveyed to, and deposited in the various organs of the body.