Wait, how did no one know about this?!
The student, Zachary Turpin, searched the databases using some of Whitman;s pseudonyms, in this case Mose Velsor. After seeing a reference to a health series by "Velsor," he requested microfilm of the New York Atlas. The rest is manly health history.
This isn't some sort of "maybe it's Walt Whitman" situation, either; Whitman had referenced "manly health" in other works, because when you write a manifesto about manly health, you CAN'T STOP WRITING ABOUT MANLY HEALTH. Also, only Walt Motherfucking Whitman would use the word "multitudinous" in the opening paragraph of a health manifesto, and you don't exactly need to be a literary historian to see through that bit of diction. He might as well have called it "Song of My Health."
This is probably no-nonsense, technical, dry health-speak from the 1850s, right?
Wrong! Don't ask stupid, leading questions, idiot straw man. In addition to the opening salvo of "multitudinous," Whitman gives you the full range of his florid health prose, including speculation on why the heck men want bulging, veiny muscles in the first place:
"[A]ll other goods of existence would hardly be goods, in comparison with a perfect body, perfect blood -- no morbid humors, no weakness, no impotency or deficiency or bad stuff in him; but all running over with animation and ardor, all marked by herculean strength, suppleness, a clear complexion, and the rich results (which follow such causes) of a laughing voice, a merry song morn and night, a sparkling eye, and an ever-happy soul!"