Andreas Whittam Smith: Paintings that really are worth saving for the nation

Am I saying that I would rather keep a set of book illustrations by William Blake than a Raphael? Yes

The forthcoming sale of a set of 19 watercolours by William Blake in New York will be a serious loss to this country. I am not usually a nationalist so far as works of art are concerned. I didn't support the campaign to retain Raphael's Madonna of the Pinks when it was put up for sale by the Duke of Northumberland, masterpiece though it is. For at the time there were already nine Raphaels hanging on the walls of the National Gallery.

But work by William Blake is a different matter. For Blake, the poet and painter, is an important part of our history. I am not happy that the Madonna of the Pinks was saved for the nation while the Blake watercolours are leaving these shores despite efforts to retain them. Am I really saying that I would rather that Britain kept a set of book illustrations by William Blake - for that was the intended role of the 19 watercolours - than one of the great examples of Renaissance art? As it happens, yes.

These 19 watercolours depicting angels, arm-linked spirits, elaborate tombs and moonlit graveyards, all in greys and black and pastel colours, have twice had a lively history, first in 1805 when they were created and then when they were rediscovered after nearly 200 years of oblivion.

Blake was commissioned by Robert Cromek, a plausible Yorkshire engraver turned businessman who established himself in London as a publisher of illustrated books. Cromek asked for 40 illustrations for Robert Blair's poemThe Grave, which, albeit a meditation on mortality and redemption, had sold well, going through many editions.

Blake drew his inspiration from studies of tombs he had made in Westminster Abbey when he was an apprentice. It was this experience that confirmed his conviction that "Gothic is Living Form ... Eternal Existence." Out of the finished designs, Cromek chose 20 at a modest price. But Blake expected to engrave his own work, making the whole job worthwhile. Cromek, however, didn't like Blake's unconventional engraving techniques and went elsewhere, not even acknowledging Blake's role in his edition of the poem. Blake was naturally furious and wrote these lines in his notebook:

"Cr... loves artists as he loves his Meat; He loves the Art but tis the Art to cheat A petty Sneaking Knave I knew O Mr Cr... how do ye do?"

Walter Scott, by the way, had come to the same opinion: "Cromek is a perfect Brain-sucker living upon the labour of others."

After Blake's death, all but one of the 20 watercolours disappeared from sight. Only The Widow Embracing Her Husband's Grave, now hanging in the Yale Centre for British Art, remained in public view. The other 19 re-emerged in 2000 when a house was being cleared after the owner's death. The story then resumed in the same manner as it had started - wrangles over money, suspicion, accusations and despair.

The new owners took the portfolio to a Glasgow shop specialising in children's books and second-hand academic works. There it remained for a year until two Yorkshire booksellers turned up and thought the contents looked interesting. They took them to book auctioneers in Gloucestershire, who in turn showed the portfolio to the Tate Gallery and to a Blake scholar. So far, so good. The watercolours had been found again, they had been authenticated and they had been shown to the appropriate national institution.

The next step was that the Yorkshire booksellers decided to put the watercolours up for auction in Gloucestershire and at the same time ask the Tate whether it was interested in buying them. The Tate offered £4.2m, which it didn't have but would have to raise; it was given five months to do so. Again, nothing to complain about. But now the Glasgow bookshop and the Yorkshire dealers fell out over ownership, started legal actions and settled before the court case could begin. The auction was cancelled. The Tate pressed on with raising the funds.

Then came the fateful intervention. A London art dealer representing a group of investors stepped in. In the financial markets these are called vulture investors; they fly high above the ground looking for carcasses to pick clean. Knowing the strong market for Blake's work in the US, knowing that the collection could be broken up and the 19 works sold off one by one, they swooped in with a higher offer. Twice the investors applied for an export licence; twice the Government refused in order to give the Tate the time to match the offer. But the investors raised their price even higher, effectively shutting out the Tate. Finally the Tate gave up and an export licence was granted in September. Last week it was announced that the watercolours would be sold separately in New York in May.

It is a sad story. This is the William Blake who gave us "Jerusalem" - "and was Jerusalem builded here among these dark Satanic mills?" - and "The Tyger" - "what immortal hand or eye could frame thy fearful symmetry?"

There are no real villains in the story. Cromek was no more than "fly". Art investors have a perfect right to make money where they can. The Tate was on the case from an early stage. The export licence machinery worked as it should, albeit unsuccessfully on this occasion. I just wish the Tate had banged the drum louder. The story remained below our radar screens until last week. By then it was too late.