LXXXIV. Fourthly and lastly, that through whatever channels you suppose the humour to pass; how does it happen, that neither in them, nor the parts immediately connected with them, it does not excite any sensations, but that sore feelings, are only perceived at the part where it vents itself? Is it not totally incredible, that a very acrid humour derived from the head, and which flows to the stomach, to the breast, to the intestines, and even to the extremities of the feet, should produce no sensations in the intermediate parts between the head, and the place on which it falls? This difficulty, which occurred to me many years ago, I have often mentioned to medical people, but never could get any solution of it that was satisfactory to me. LXXXV. If by way of objection to what I have here advanced, the argument we have mentioned before is urged, that defluxions on any part of the body are generally attended with a pain in the head; I answer, that it cannot be inferred from thence, that the humour descends from the head. In the first place, for I have observed it many times with regard to myself, these fluxions are often not attended with any pain in the head at all; and to make the inference just, they should always be attended with one. Secondly, although a pain in the head should constantly accompany a defluxion, the objection made would easily be removed, by saying, that this appearance is fallacious, for that both the pain and the defluxion, are effects of the same cause, and not one the cause of the other. In fact, reason tells us this is the case; for the acrid humour, which when separated from the mass of blood, falls on, and discharges itself at this or that place, while it continues in the circulation, has nothing to hinder it from venting some portion of its poison on the head, and exciting pain there; and especially, as it is generally supposed, the nidus of the humour which flows in defluxions, is in the glands, and the brain holds the first place in that class; for which reason, Hippocrates and Wharton, call it the great and principal gland.