Contact John barton

Use the form here for correction requests, dead links, or legitimate scholarly questions about our reference material.

Urgent health matters should go to a qualified healthcare professional without delay.

Archive continuity: Historical continuity notice: We preserve independently edited reference material for readers studying science and history. Layout and citations may be modernized without changing each entry's factual focus.

From the archive

We update this list from time to time as additional reference pages go live.