The immediate cause of the separation was that Wharton had forbidden his wife to come to London where small-pox was raging at the time.

She, however, whether irked by the dulness of the country, or thinking by her presence to guard her husband against those temptations to which he was prone, followed him to the town, where the infant sickened of the epidemic and died.

After one great scene, they never met again.
There is mention of the Duke in another letter of Lady Mary to Lady Mar, dated February, 1724: "In general, gallantry never was in so elevated a figure as it is at present.

Twenty very pretty fellows (the Duke of Wharton being president and chief director) have formed themselves into a committee of gallantry.

They call themselves _Schemers_; and meet regularly three times a week, to consult on gallant schemes for the advantage and advancement of that branch of happiness....