A good example of this process comes from the writing of Asher B. Durand (1796-1886) in his "Letters on Landscape Painting," 1855. In a passage where he described the joys of picture-gazing, he wrote that the viewer
“becomes absorbed in the picture—a gentle breeze fans his forehead, and he hears a distant rumbling [from] far away in the haunts of his boyhood—and that soft wind is chasing the trout stream down the woody glen, beyond which gleams the ‘deep and silent lake,’ where the wild deer seeks a fatal refuge.”
This sense of art’s power to charm the soul risks sounding sentimental to our modern ears, accustomed as we are to a very different aesthetic culture. And perhaps it did so even to Durand himself in 1855, when he said, “I need scarcely apologize for the seeming sentimentalism of this letter. In this day the sentiment of Art is so overrun by the the technique, that it can scarcely be insisted upon too strongly.”
Image is by Arthur Parton (1842-1914), "Summer Afternoon on the Delaware," 1879.
American Artist has an excerpt of "Letters on Landscape Painting" here.
Linda Ferber's recent book "Kindred Spirits: Asher B. Durand and the American Landscape" has the full text printed in an appendix.