This is not my hoped-for exhibition of pre-Pre-Raphaelites and the boys’ responses to them, nor of their early work  before the idea of Pre-Raphaelitism seized them, nor of the changes wrought by whatever was in their unwritten manifesto; of the 175 exhibits listed in the catalogue only 20 represent the five years of the Brotherhood’s existence. Had these been hung together, combining in their impact to engender acute insights in terms of realism, emotion, colour, light and technique, we might have identified the probable declarations of the absent   manifesto; but they are instead scattered to illustrate such imposed themes as Salvation, Beauty and Paradise, all chronology discarded.

Even with so few there are significant absentees from the precocious Millais’s tally — The Proscribed Royalist, several portraits and landscapes, and above all, The Bridesmaid (with which he set a pattern for the half-length sensual women of his peers); and had his boyhood masterpiece of 1846, Pizarro Seizing the Inca of Peru, been included to demonstrate how great was the leap to his Isabella and the Pot of Basil of 1848-49, it would have been worth a thousand words of exegesis. This last, dubbed by Hunt “the most wonderful picture that any youth of 20 years of age ever painted”, perfectly demonstrates the Brotherhood’s infatuation with Italian art and literature before the High Renaissance, the subject Boccaccio’s tale of love and murder, the costumes pseudo-Quattrocento, the realism and the differentiated profiles wholly of Millais’ 19th-century day. We can almost hear the scrotum crunch of the walnut in the cracker, and we fear for the sleeping dog under the murderer’s tilted chair. Always illustrated in seemingly misleading brilliant colour, it is so tonal as to suggest a substantial layer of grime — an impression heightened by the curators’ comparison with the scrubbed Lorenzo Monaco borrowed from the National Gallery.

In terms of tone and colour, Millais proves to be surprisingly inconsistent, Hunt far less so — indeed Hunt in this exhibition emerges as a pure Pre-Raphaelite for far longer than Millais  and never as drab (except in The Awakening Conscience); visitors may be surprised too by the drabness of Rossetti’s watercolours. Poor visitors — the Tate last offered them a comprehensive review of the Pre-Raphaelites in 1984, yet after a lapse of 28 years, all will leave this exhibition in confusion as absolute as mine in the year of their centenary, indeed worse, for they will have no idea of what is meant by the subtitle, Victorian Avant-Garde. Comparing Holman Hunt’s Hireling Shepherd, the bright peasantry blatantly lustful in the meadows between Kingston and Ewell, with the mysterious dooms and glooms, romantic, symbolic and Wagnerian, of The Perseus Cycle by Burne-Jones, 35 years later, they will discover no connection, for by then the essential fire of the Brotherhood had long since fizzled out.