The teeth are in the respective zones as indicated by passing a line antero-posteriorly thru the respective zones. The viscera are in the zones as represented by a line passed antero-posteriorly thru the respective zones. FIG. 1.] [Illustration: Diagram of *Posterior Zones* on one side of the body. Both right and left sides of the body are the same. Each numbered line represents the *center* of its respective zone on the posterior part of the body. The under surface of the tongue is in the posterior zone. FIG. 2.--Posterior view, illustrating individual zones. It will be observed that what is commonly called the back of the hand is really the front of that member, whereas the palm of the hand corresponds to the sole of the foot.] CHAPTER I. RELIEVING PAIN BY PRESSURE. No illustrator would ever think of drawing a picture of a boy with a green-apple colic, unless he represented that boy with both hands clasped fervently over the seat of war. Nor would he picture a pain anywhere else, without showing the attempts made to relieve this pain. For no one would believe his illustrations, if he omitted these details. Now, while we know the fact of pain relief, through laying on of the hands, or by kindred measures, we know only a part of its reason for operation. There are several of these. They are, first, the soothing influence of animal magnetism, experienced when we tenderly, if not lovingly, rub the bump, accumulated in the dark of the moon, by collision with a tall brunette side-board, or a door carelessly left ajar. It does soothe. This we know. Next, the manipulation of the hand over the injured place tends to prevent a condition of venous stasis--a state in which the injured surface veins dam back the flow of blood, and produce that lurid discoloration known euphoneously as “black and blue.” Also, pressure applied over the seat of injury produces what Dr. George W. Crile, of Cleveland, calls “blocked shock,” or “nerve block,” which means that by pressing on the nerves running from the injured part to the brain area we inhibit or prevent the transmission to the brain the knowledge of injury. In other words, the hurt place can’t tell the central telegraph station anything about the accident, because the wires are down. Dr. Crile, and surgeons generally, now utilize this knowledge to prevent shock during operations, by injecting cocain, or some anesthetic solution around the course of the nerve trunk leading from the place to be operated upon to the brain. But there is yet another reason, which we have found out only yesterday. And this is zone analgesia. Pressure over any bony eminence injured, or pressure applied upon the zones corresponding to the location of the injury, will tend to relieve pain.