Robert Henri, founder of the Ashcan School, is a complex figure in American art. A visionary writer on art, he pushed for the introduction of fashionable European painting modes at a time when they were ill-received in the United States. His painting, falling in the wrong gap between the Impressionists and everything that took the twentieth century by storm, is often ignored by critics. Which is unfortunate, as they display an acute atmospheric sensitivity.
There's something in Willem Kalf's handling of liquid that confounds perception. Examine the glass in Still Life With Chinese Bowl (1662). Liquid is represented as liquid interacting light, rather than form. Not sculptural, but not symbolic.
Disquieted, at the Portland Art Museum, suffers from a lack of overall coherence but is jam-packed with great artworks. Tracey Emin, Bill Viola, and Jan Tichy contribute the most effectively 'disquieting' works.