Page 4 - TheOperatorfortheTeeth

same manner that Enamel does upon gold, or any other thing; This natural enamel which I call the gloss of the tooth, is of a far harder, whiter, more dense and lucid nature that the inward substance lying under it: which for its several uses may properly be compared to the Cuticula, or Scarf-Skin, for like unto this is it bloodless, and altogether destitute of sense, serving to cover and defend the extremities of the vessels contained within the inward substance, from external injuries: And to render the tooth more beautiful and strong. It has pores for the perspiration of the excrements of the tooth, which pores are not always of the same figure or magnitude, but vary almost in every body. The said gloss or stony substance is likewise very various in point of thickness: from which differences do arise the diversity of its colour in several men. The inward part of the head of the tooth; though inferior to its cover or gloss in brightness and solidity: yet its substance is nevertheless much more compact, and clearer than that of the stump: and contains several sorts of pores, or small channels both of a conical figure, having their bases in the concave superficies of the tooth, and their apexes in the convex superficies of the inward substance, immediately under its glassy integument. Through some of which channels, the blood is carried away by many and very small arterial sprigs, from the middle of the tooth to its extremity: and through the others the same blood is sent back again from the said extremity, towards its middle; by some capillary veins as shall be said hereafter. As to the root or stump of the tooth; it is the darkest, most soft, and porous portion of its whole substance: and yet it is closer and harder than any other bone of the body, having also two sorts of channels, but of different situation from one another: for some of them have their bases (like those above described) towards the cavity of the tooth, and contain the branches of the artery, that carry the blood quite through the substance of the tooth, to the gums, as shall be explained in its place; but the others contrary to any of those already mentioned, have their bases towards the external superficies of the tooth; the use of which last conduits, is to transmit to the gums the blood that is returned to the heart from the membrane that invests the cavity of the tooth. This rooty part of the tooth, consists in the small teeth of a single body: and in the big ones is divided into two, three or four branches, called roots or fangs: along the middle of each of these fangs, there is a little channel that goes up to the head of the tooth; where they are united together, and make but a single cavity, whereinto are carries the vessels of the tooth: passing first through the hollowness of the stumps. Every tooth has its particular cell or socket within the mandible: distinct from all the rest (bu a thin production of the jaw-bone, passing between the teeth, from one side of the said bone to the other) wherein most of the stump is comprehended, the rest being incompassed about with the gums. [3]