failed attempts to explain the enormous energy radiated from the sun using classical physics, eventually settling on the heat given off by incoming meteor collisions as the most likely explanation. And it is occasionally visionary, as when Ludlow, decades before Albert Einstein would do the same, abandons the idea of the æther and muses that “[w]e might be allowed to… assert that because our only cognitions of matter are cognitions of force, matter in the scientific sense is force.” He does not elaborate, and evidently the article was altered and cut for publication substantially, so we are left to wonder how far he pursued this idea of the equivalency of matter and energy. Homes for the Friendless One of the last published pieces by Ludlow was written for the New York Tribune, and published early in the year of his death. Probably prompted by his work with destitute opiate addicts, the article, “Homes for the Friendless,” advocated the establishment of homeless shelters in New York City, particularly for alcoholics and other drug addicts, noting that the existing shelters served women and children only, and that there was a growing class of homeless men in need of assistance. The idea was enthusiastically endorsed in an editorial by Tribune editor Horace Greeley. Final years The last years of Ludlow's life seem to have been a constant struggle with addiction. Family letters, when they mention him, usually either hopefully discuss his latest release from habit or mourn his latest relapse. His cousin wrote in March 1870, that “Dr. Smith has been treating him for a while but he said to a lady the other day — that there was no use in his wasting his strength [treating] Mr. Ludlow, for he took a teaspoonful of morphine in a glass of whisky every day — and while he persisted in doing that it was only time & strength thrown away…” His writing focus, as well as the focus of his life, turned to the problem of opium addiction. He described this as “one of my life’s ruling passions — a very agony of seeking to find — any means of bringing the habituated opium-eater out of his horrible bondage, without, or comparatively without, pain.” His essay What Shall They Do to be Saved from Harper’s was included in the 1868 book (written by Horace Day, himself a recovering addict) The Opium Habit, one of