From Public Advertiser ( London, England ), Thursday, July 29, 1756; Issue 6771.   We hear from Nettlebed in Oxfordshire, that on Thursday last Mr. William BUTLER , of Crockerend, in that Parish, having mixed Poison with some Oatmeal to destroy the Rats, a Maid-Servant, who was not acquainted with the Mixture, made use of the Meal for Breakfast.  The Maid herself died in great Agonies that Night; but by the Assistance of Mr. NORTON , Apothecary at Henley, 'tis hoped that two Men-Servants, who also partook of it, will recover.