FOR as we divide the _Course_ of the _MOON_ by _4 Weeks_, according to its 4 quarter _Changes_; so we distribute the _Course_ of the _SUN_ into _4 Stations_, according to the _four Seasons_ of the Year: Hence it is that all _Times_ of the _Year_ answer in proportion to the different _Weeks_ of the _Month_, and all _Stations_ of the _SUN_ (in like manner) to the different _Changes_ of the _MOON_. Wherefore as the _7th Day_, which is the 4th Part of the _Lunar Month_, determines _acute Distempers_; so the _Change_ of the _Season_ of the Year dissolves _Diuturnal Diseases_. The _SPRING_ commonly shakes off any _Malady_ generated in _WINTER_, as the _SUMMER_ does what is begun in the _SPRING_; and the _AUTUMN_ discusseth any _Affection_ excited in _SUMMER_, as the _WINTER_ does what happen’d in _AUTUMN_.
THESE Things being thus cleared-up by the way, we have now only to consider, that the Time of _GESTATION_ is no _Acute_, but a _Diuturnal Effect_; and that BIRTH is nothing else but the CRISIS of the same _Affection_, according to[140]_Hippocrates_’s Sense. Which, if so, it is evidently manifest that, in defining the _Time_ of BIRTH, we ought chiefly to regard the _Course_ of the _SUN_, and strictly observe the _Number_ of _MONTHS_; However so, as not to neglect the _Motions_ of the _MOON_, and consequently, we ought also to consider duly the neat _Number_ of _DAYS_: Wherefore (I say) in BIRTH we are to have a just Regard to, and take a strict Observation of, not only the _Changes_ of the _MOON_, but also of the _Mutations_ of the _SUN_; because both the _One_ and the _Other_ act very powerfully in _BIRTH_. Which I thus beg leave to illustrate as follows, _viz._
AS the _first seven Days_ have the greatest Power of determining _Acute Diseases_, so the _first three Months_ of _GESTATION_ (which answer to those Days) determine the _CONCEPTION_: And as of _those_ the _7th Day_ is the most powerful, so of _these_ the _third Month_ is the most prevalent. From hence it is that the FOETUS suffers such manifest _Alterations_ and _Changes_ of Nature in this MONTH: For it is now metamorphos’d or chang’d from an _Inanimate_ into an _Animate Being_: It now becomes a _Living_ and _Moving Body_, subsisting henceforward by its own proper vivacious _Faculties_; yet not so however, that _this_ MONTH can be presum’d to produce a _vital Birth_: No, because as every perfect and plausible _CRISIS_ of the _7th Day_, requires the _Concurrence_ of the digested _Humour_, together with the _Ability_ and _Strength_ of the _PATIENT_; so in BIRTH, the _Disposition_ of the _INFANT_ must necessarily concur with all _These_, which it can never be suppos’d to do in the short Space of _Three Months_.
