_Symphysis_ is the uniting of two Bones by the interposition of a _Medium_, which ties them very streight together, being also threefold: Such is the Connexion of the Knee-Pan or Whirl-Bone of the Knee, and the _Omoplata_ or Shoulder-Blade. _Are not these three kinds of Articulations or _Symphyses_ distinguish'd one from another?_ Yes; for tho' they are all made by the means of a third Body intervening, which joins them together; nevertheless every one of these various Bodies gives a different Denomination to its respective Articulation: Thus the Articulation which is caus'd by a Glutinous and {16} Cartilaginous Substance, is properly call'd _Synchondrosis_; as that of the Nose, Chin, _Os Pubis_, _&c._ But an Articulation which is made by a Ligament is termed _Synncurosis_, as that of the Knee-Pan. Lastly, that which is wrought by the means of Flesh, bears the Name of _Syssarcosis_; as the Jaw-Bones, the _Os Hyoides_, and the _Omoplata_ or Shoulder-Blade. _Have the Bones any sense of Feeling or Motion?_ They have neither; for their sense of Pain proceeds from nothing else but their _Periostium_, or the Membrane with which they are cover'd, and their Motion is perform'd only by the Muscles that draw them. _Doth the Marrow afford any Nutriment to the Bones?_ No, all the Bones are nourish'd by the Blood, as the other Parts; but the Marrow is to the Bones what the Fat is to the Flesh; that is to say, it is a kind of Oil or Unctuous Substance, which moistens, and renders them less brittle. _Are all the Bones of the same Colour?_ No, they follow the Temperament and Constitution of the Persons. _How many in number are the Bones of the Humane Skeleton?_ There are two hundred and fifty usually reckon'd, _viz._ 61 in the Head, 67 in the Trunk or Chest, 62 in the Arms and Hands, and 60 in the Legs and Feet; but the true Number cannot be exactly determin'd, by reason that some Persons have more, and others fewer; for some have more _Ossa Sesamoidea_, Teeth and {17} Breast-Bones than others: Again, some have many indentings in the _Lambdoidal_ Suture, and others have none at all. _Can you rehearse the Number of the Bones of the Head?_ There are Fifteen in the Skull, and Forty six in the Face. The Fifteen of the Skull are the _Coronal_ for the fore-part of the Head; the _Occipital_ for the hinder-part; the two _Parietals_ for the upper-part and each side; the two _Temporals_ for the Temples; the _Os Sphenoides_ or _Cuneiforme_, which closeth the _Basis_ or bottom of the Skull; the _Os Ethmoides_, or _Cribriforme_, situated at the Root of the Nose; and the four little Bones of the Ear on each side, _viz._ the _Incus_ or Anvil; the _Stapes_ or Stirrup; the _Malleolus_ or Hammer; and the _Orbiculare_ or Orbicular Bone.