THE BRONTË Society has bought an envelope addressed by Charlotte Brontë at a private auction in Wiltshire.

The envelope was one of two written by Charlotte that were auctioned on Saturday for a total of £8,100.

The one bought by the Brontë Society, which runs the Brontë Parsonage Museum in Haworth, is post-marked 30 January 1849 and is addressed to Charlotte’s lifelong friend Ellen Nussey.

Charlotte’s sister Emily died the previous month and the envelope has a black border and the remains of a black seal.

Anne Brontë had recently been diagnosed with TB and it appears that Ellen has written a pencilled note on the envelope, stating that the contents discussed Anne’s condition.

Charlotte and Ellen met each other at Roe Head School near Mirfield in 1831 and wrote to each other regularly until Charlotte’s death in 1855.

Ann Dinsdale, Principal Curator at the Brontë Society, said the envelope was significant because it attested to the lifelong friendship between Charlotte Brontë and Ellen Nussey.

She said: “The two women lived almost 20 miles apart and visits were often difficult to arrange due to the lack of available transport or family obligations, so letters became the primary means of keeping in touch.

“Charlotte’s correspondence with Ellen was a huge support to her through the terrible loss of her brother and her two much-loved sisters over a nine-month period."

Ms Dinsdale said that although the Brontë Society had a significant number of Charlotte’s letters, its collection did not include one corresponding to this particular envelope.

She added: “We now know there was a letter which is missing, or that the date assigned to an existing letter is incorrect.”

The item will go on display next year at the Brontë Parsonage Museum, which houses the world’s largest collection of Brontë papers and personal possessions.

The envelope was discovered in the attic of a collector in the United States. A second envelope auctioned at the same time by Henry Aldridge and Son in Devizes was purchased by an unknown bidder from the south of England.

The pre-auction estimates for each envelope was £800 to £1,200,

The envelope now owned by the Brontë Society is written in brown ink, has a Penny Red stamp and is postmarked "Leeds Jan 30 1849" and "Barnsley Keighley and Haworth" with the remains of a black seal.