Hello PIGs My fifth essay is now posted to the PIG website. The essay mostly pertains to Jahns' first two publications in a professional journal. I also comment on another article by Abe Heinrich that was published in the same year, 1953. The three articles are available on the PIG site in PDF by permission of the editors of American Mineralogist. David London Learn about pegmatites and join the Pegmatite Interest Group at http://www.minsocam.org/msa/Special/Pig/