HAVING particularly defin’d the Natural Conception, in Chap. I. Sect. III. and hitherto treated of its various different Consequences, both in Gestation, Birth and Child-Bed; I come in the next place (conformable to my promise before-mentioned) to treat of the opposite and reverse Case, commonly call’d (by the Authors) a vitious or depravated Conception: Which however, I shall distinguish by the general Title of præternatural, as I have one Set of Births under the same Denomination, contained in Sect. V. But——

NOW, because I judge all such Conceptions as well as Births, to be præternatural, which, tho’ not according to the ordinary Institution of Nature, are yet however not repugnant to Nature: And because such Conceptions, as well as the Præternatural Births already defin’d, happen after many different ways and manners; I shall also reduce and divide them into two Classes, viz.——

FIRST, Præternatural Conceptions in respect of the Number; to which belong all Superfætations, and other Numerous Conceptions; And Secondly, Præternatural Conceptions in respect to the Form or Substance; to which belong all false Conceptions, Moles, Monsters, &c. Of all which particularly and briefly in their due Order, and First——

CHAP. II.
Of SUPERFÆTATIONS.

A Superfætation is nothing else than a Second (after a First) Conception: Since if divers Infants may be conceiv’d at one Embrace, as will evidently appear from the following Chapter, we may easily believe, that two, three, or more Embraces, may most probably have the same Effect: Which is sufficiently confirm’d by the Experience of Hippocrates[[195]] himself, as well as by many other most Learned Authors[[196]].

WHEREFORE I shall spend no time in reciting here any Instances I have met with of this Nature; only I refer the Curious to a very famous collected History of such Births, as in the Margin[[197]]. Whence the Certainty of Superfætation is not to be doubted, and much less to be disputed: And according to Aristotle the same may happen, after the Second or Third Day, from first Conception, as well as after so many Months[[198]]. But farther,——

THE Cause of all Superfætations is only an Apertion of the Orifice of the Womb, at the Effusion of the Virile Seed. Which however (according to Avicen) only happens to such Women, as have plenty of Blood, or a Calid Womb, desirous of Copulation, or to such as have their Menstrua after the first Conception.

SUPERFÆTATIONS however are not easily discover’d before Birth; at which time, Avicen advises to take Notice of the Navel-String; For (says He) if it be without folds or wrinkles, there is but one Child; if otherways, there’s a Child for every Wrinkle: But I think the expert Midwife using her Hand, as I have not unadvisedly inculcated[[199]], will have but small Occasion for such Observations, and far less Need to trust to them.

BUT when more than one Child is found, they are distinguishable, (I mean Superfætations) from These conceiv’d at one time; those having each a peculiar Secundine; these One only in Commune: As the one is also less vital and more imperfect, than the other; according to the interval of Time betwixt their Conceptions.