One statement needs correcting as to point of fact: It is stated (on page 5) that James Boyd died "in a mental institution". In fact, he died (on 11 April 1936) at the home of his daughter and son-in-law, Mr Robert A & Mrs Kathleen Blakeborough, 'Raths-Rigg', Shepherds Thorn Lane, Brighouse, Yorkshire, England. [source GRO death certificate]

Was he in a mental institution before his death?

Leslie M. Grant was a signatory to this tract. His writings are not featured on this site. Any reason? He has some helpful commentaries. See https://www.stempublishing.com/authors/grantlm/index.html

Generally can't put modern writers up due to copyright, though the fact it's on Stem would suggest it's in the public domain. Still there would be publishers copyright on any edition published within last 25 years.