The Influence of the Blue Ray of the Sunlight and of the Blue Colour of the Sky (cover title: Blue and Sun-Lights: Their Influence Upon Life, Disease &c.)

First trade edition, identified by the author in the preface as the second edition following the text's dissemination amongst the scientific community. Frontispiece in blue and black, and at least one in-text illustration. About Very Good with sunning around the edges of the cloth; bumping and slight fraying to corners. Printed in blue ink—the author's endeavor to lessen eye strain when reading by flame at night—but quickly faded and rendered the text nearly illegible. Later editions were printed on blue paper with black ink.

Pleasonton was a former Union Army general who left the service to practice law, but ultimately became obsessed with the amateur scientific investigations he undertook on his farm outside Philadelphia. He was convinced of a connection between blue light and the development of organisms. In 1861, a blue glass house was built for an experiment in cultivating grapes, then livestock, and ultimately applied to humans. The apparent success of his endeavor led to a "blue glass craze" that crested with Pleasonton's publication in 1876, then fizzled after years of criticism built to a definitive debunking of the theory by Scientific American in 1877. As summarized in Pleasonton's obituary in the New York Sun: "The basis of General Pleasonton's theory was the difference in the action of the various rays of the spectrum. In his lecture, he said the sky was remarkably blue at the equator and in the Arctic regions, and the exuberance of vegetable growth in the region of the former and the rapid growth of vegetable life in the latter was said to be unequaled in any other portions of the globe. From this the lecturer said it would be easy to imagine the enormous influence exerted by the blue of the sky, combined with the sun's white light and heat and the moisture of the regions. As an example of this influence, General Pleasonton brought forth the subject of the green color of the leave of plants. Blue combined with yellow makes green, being darker when blue predominates and the reverse when yellow is in excess."