James H. Schmitz 
Ham Sandwich [EPUB ebook] 

(Excerpt): "In addition, Perrie and Dexter were volunteers for what Dr. Aloys Ormond referred to cryptically as "very advanced experimentation." The group at large had not been told the exact nature of these experiments, but the implication was that they were mental exercises of such power that Dr. Al did not wish other advanced students to try them, until the brave pioneer work being done by Perrie and Dexter was concluded and he had evaluated the results."