The artist's work of the last two decades of his life show an increase in the scale of the paintings and drawings; a marked tendency to leave untouched, large areas of white-primed canvas; the abundant use of black pigment or ink, sharply contrasting with the white of the canvas or sheet; and the use in their creation of palette knife, builder's trowel or broad brush. This work displays many of these characteristics and so too does Earth, Air, Fire and Water (National Gallery of Modern Art, Edinburgh). Is it perhaps possible to interpret this work as showing a cycle of nature: evaporation, cloud formation and rain? Even Johnstone's most extreme abstractions usually contain reference to landscape elements. These magnificent, late, large-scale, abstract-expressionist works were executed in rural areas of Scotland, Potburn or Crailing, by a man known in the local community of his birth only as an elderly or retired farmer. To its loss, the paintings were virtually unknown to the artistic world beyond.