Oil on board. 18 x 15in. (45.5 x 37.5cm.) Signed and dated: ‘Colquhoun/36’ lower right. Titled verso. Provenance Sotheby’s, studio sale, 24 April 1985, lot 482, ill. b/w The Pruskin Gallery, London. Exhibited London, Mayor Gallery, 1939, no. 8. Harrogate, Art Gallery, 1941, no. 23. London, Leva Gallery, 1974, no. 6. Penzance, Newlyn Gallery, 1976, no. 6. London, Parkin Gallery, 1977, no. 13. London, Blond Fine Art, 1985, no. 37. According to the Parkin Gallery catalogue, the work was exhibited at the Hamet Gallery in 1971. If so, it was ex catalogue. Rails, Corner (1937) and Philosopher’s Stone (1942), with their transparent overlapping planes and spatial ambiguities, are more likely to reflect an occult interest in the solidity of the material world than an otherwise unrecorded interest in cubism, as it is also found in works such as Figure in a colour cube (ca. 1941) and Towards the Tessaract (1978) which have a clear occult focus.