Following Rachel's post below, this is the exact copy of Jane Austen's letter to Cassandra, on 23 August 1796, seven months after the last surviving letter dated January 16, 1796 when Jane talked of her broken heart. I found this in 'Jane Austen's Letters (Chapman, 1979), page 7. No date was found in Chapman's book, only month and year, but Walker's (2007) article suggested that the date was 23 August 1796.
My dear Casandra
Here I am once more in this scene of dissipation and vice, and I begin already to find my morals corrupted. We reached
Edward and Frank are both gone out to seek their fortunes; the latter is to return soon and help us seek ours. The former we shall never see again. We are to be at Astley’s to-night, which I am glad of. Edward has heard from Henry this morning. He has not been at the races at all, unless his driving Miss Pearson over to Rowling one day can be so called. We shall find him there on Thursday.
I hope you are all alive after our melancholy parting yesterday, and that you pursued your intended avocation with success. God bless you! I must leave off, for we are going out.
Chapman, R. W. 1979, Jane Austen's Letters to Her Sister Cassandra and Others, 2nd edn, Oxford University Press,
Walker, L. R. 2007. 'Jane Austen and Tom Lefroy: Stories', Persuasions On-line, vol. 27, no. 1. Available: http://www.jasna.org/persuasions/on-line/vol27no1/walker.htm