The Healthian was a "journal of human physiology, diet, and regimen" that was written by the great thinkers living in the Alcott House. The Alcott House was created in London, England, and was based on the principles and philosophies which American Transcendentalist Amos Bronson Alcott taught at his most famous teaching experiment, Temple School.
In 1841 the students began to print pamphlets called The Healthian, which would eventually be consolidated into an annual volume. The writings matched Alcott's vegetarian principles and advocated for the animal-free lifestyle that we know today as "vegan."
This is a screenshot of Volume 1, No. 1 of The Healthian, "a journal of human physiology, diet, and regimen." A quote by Amos Bronson Alcott can be seen before the introduction. The word "vegetarian" first appeared in a section called Flesh Diet in Volume 1, No. 5 of The Healthian, in April 1842.