Lady Mary Duncan, the great patroness of Pacchierotti, was one of the most singular females of her day, for parts utterly uncultivated, and mother-wit completely untrammelled by the etiquettes of custom. She singled out Dr. Burney from her passion for his art; and attached herself to his friendship from her esteem for his character; joined to their entire sympathy in taste, feeling, and judgment, upon the merits of Pacchierotti.

This lady displayed in conversation a fund of humour, comic and fantastic in the extreme, and more than bordering upon the burlesque, through the extraordinary grimaces with which she enforced her meaning; and the risible abruptness of a quick transition from the sternest authority to the most facetious good fellowship, with which she frequently altered the expression of her countenance while in debate.

Her general language was a jargon entirely her own, and so enveloped with strange phrases, ludicrously ungrammatical, that it was hardly intelligible, till an exordium or two gave some insight into its peculiarities: but then it commonly unfolded into sound, and even sagacious panegyric of some favourite; or sharp sarcasm, and extravagant mimicry, upon some one who had incurred her displeasure. Her wrath, however, once promulgated, seemed to operate by its utterance as a vent that disburthened her mind of all its angry workings; and led her cordially to join her laugh with that of her hearers; without either inquiry, or care, whether that laugh were at her sayings or at herself.

She was constantly dressed according to the costume of her early days, in a hoop, with a long pointed stomacher and long pointed ruffles; and a fly cap. She had a manly courage, a manly stamp, and a manly hard-featured face: but her heart was as invariably generous and good, as her manners were original and grotesque.