MOST, if not all, _Authors_ having hitherto imagin’d, that all _Preternatural BIRTHS_ took their sole _Rise_ and _Origin_ from the wrong _Positions_ of the _INFANTS_ only; I come in this place, with all due Submission, not only to affirm a quite contrary _Opinion_, but also to lay down a directly opposite MAXIM: Namely, that the most difficult and dangerous _Preternatural BIRTHS_ proceed merely from the ill _Situation_ of the WOMB; which I take to be the most common _Cause_ of the CHILD’s wrong _Posture_. The Truth of which I hope to make evidently appear, to all such, who know and will consider, that this _Noble Part_ is no less subject to various _Accidents_ and different _Diseases_, than the _Rest_ of the BODY; which springing from divers _Sources_, may rationally be suppos’d to occasion _Preternatural BIRTHS_, and _those_ more or less dangerous, according to the _Nature_ of the EFFICIENT: as for _Instance_, IN _Case_ of an _Inflammation_, _Exulceration_, _Putrefaction_, or the WOMB’s being _Schirrous_, _Callous_, or _Hard_; affected with a CARCINOMA or _Cancer_; an obdurated _Gland_, _Cicatrix_, or any _carnous Excrescence_; or in _Case_ of the WOMB’s being _Dry_ and _Rigid_, and the _Orifice_’s being _Hard_ and _Thick_, as commonly happens to WOMEN _in Years_, especially of their _First CHILD_; I say, from either of _these_, or any such like _Causes_, a _Preternatural BIRTH_ may ensue, and _that_ even tho’ the PELVIS and PASSAGE be _larger_, but much more if _those_ be _narrower_, and the Point of the OS SACRUM bent _Inwards_. I. IN the _Larger_ PELVIS, the greatest _Difficulty_ of this _BIRTH_ proceeds from too great a _Descent_ of the WOMB; which relaxes the _Ligaments_ and _Fibres_ of the VAGINA, and so much depresses the _Bladder_, that an _Incontinency_ of URINE presently follows, which in this _Case_ is commonly succeeded by a _Falling Down_ of the WOMB or VAGINA, as already observ’d in _Chap._ XI. where the Diligent MIDWIFE will find the due _Method_ of preventing such growing _Mischiefs_, and of opening the _Orifice_ of the WOMB both safely and readily, and consequently _Delivering_ her _Woman_ more easily and expeditiously, with good Success as well as Security. II. IN the _narrower_ PELVIS, the _MIDWIFE_ needs no ways fear the above-named _Accident_, and therefore is not to be at so much Pains in _retaining_ the ORIFICE in its proper Place, whatever Trouble she may have in _opening_ it; which would be no easy TASK, was not the OS COCCYGIS to be _thrust back_, (as set forth, _Chap._ IX.) And which I must (for this Reason) recommend once more to all Careful _MIDWIVES_, as the best and most effectual METHOD of performing this happy _Apertion_. FROM what is said here therefore, we may now conclude, that a great _Variety_ of CAUSES may subject the WOMB to a Diversity of ACCIDENTS, and _those_ of sundry _Degrees_, which may more or less affect its _Motion_ and _Situation_, as already set forth[171].