A unique example of Samuel Taylor Coleridge's penny-a-line approach to poetry has been acquired by the Wordsworth Trust using a grant of more than £550,000 from the Heritage Lottery Fund.

The poem, part of a library of literary treasures collected by the lawyer Geoffrey Bindman and his father, is in an anthology full of forgotten works.

Called Lewti, it is based on a schoolboy poem by William Wordsworth, which Coleridge extended to fill his newspaper column. The version in the anthology is added to with lines scribbled in Coleridge's hand.

The library also holds some of the oldest printed editions of works by Wordsworth and John Keats, and a first edition of Mary Shelley's Frankenstein.

The shadow of Coleridge's chaotic life hangs heavily over the collection. It includes first editions of Lyrical Ballads, showing the last-minute panic when the title page had been printed but Coleridge had failed to produce a line of his promised epic poem Christabel. Wordsworth was forced to write his long poem Michael to fill the gap.

The library was started by Gerard Bindman in the 1920s. His son Geoffrey admitted he was not initially interested it it, but had wanted to share a hobby with his father towards the end of his life. He was then surprised to find himself gripped by the passion of the Romantics.

Mr Bindman's own children have not inherited his love for them, and the library would probably have been scattered at auction had the trust not acquired it. It will go on display at Wordsworth's Dove Cottage in the Lake District when its new reading room and archive - also backed by the lottery - open next year.