LAMENTABLE AFFAIR.—A very lamentable occurrence happened at Aust, near Thornbury, on Thursday last, to a young woman in the service of the Rev. Mr. Walters. She has very recently exhibited symptoms of insanity, and it was the intention of the rev. gentleman to remove her very shortly to her home Petersfield, Hants. She had been very placid for two or three days prior to Thursday morning last, when the poor creature went upstairs and threw herself through the window, thereby severely injuring herself, but to what extent our correspondent has been unable to learn.