The stomach forms no exception to this general law of the animal economy. When it is empty and idle, it is contracted upon itself into comparatively small bulk; and its bloodvessels become shortened and tortuous in a corresponding degree. The result is both a diminution of their calibre and a slower circulation through their branches. But when the stomach is full and active, the bloodvessels have free scope, their tortuosity disappears, their diameter enlarges, and the circulation through them becomes quicker, and fit for the rapid secretion of the mucous and gastric fluids in the quantities which we have seen to be required for the fulfilment of digestion. Accordingly, when the latter process is going on, the small arterial branches ramified on the mucous coat of the stomach become so multiplied and distended, as to impart to it a deeper red colour than it has when the stomach is empty. The increased afflux of red or arterial blood to the stomach during digestion, is not merely inferred from the analogy of other organs. Many opportunities have occurred of ascertaining the fact; and, as I shall have occasion to mention, Dr Beaumont very often SAW it take place. A corresponding change occurs in the _veins_ of the stomach during digestion. Their diameter becomes enlarged, their course more straight, and the current of blood through them more rapid. As the minute or capillary extremities of the arteries open upon the inner surface of the stomach, and there _exhale_ a fluid secretion, so the corresponding venous capillaries likewise open upon the same surface, and _inhale_ or _absorb_ fluid, which they carry into the general circulation. The rapidity with which this absorption sometimes takes place is almost incredible; for a large draught of water may be thus taken up in a few minutes. Fluids mixed with camphor or other strong-scented substance have been given to animals as an experiment, and, on killing them shortly afterwards, the peculiar smell has been detected in the blood. Most liquids are thus not digested, but simply absorbed. Rapid, however, as the process is, poisons which enter the system by absorption do not act by any means so instantaneously as those which directly affect the nervous system. * * * * * In regard to the peculiar influence which each of the NERVES ramified on the stomach exercises on its functions, much difference of opinion still prevails. We may, however, gather some useful notions by adverting to the different sources whence they are derived, and comparing these with the purposes for which we know from analogy that different kinds of nerves are required.