Warfare: as an expression of strong emotions, 286; physical and moral values claimed for, 287; barbarities of, and opposition to, 289-290; moral substitutes for, 292-293; physical substitutes for, 293-297; contrast between ancient and modern, 294-295. Witnesses: stimulating influence of, 227. Work: effect of, on neuro-muscular irritability, 117; done with use of carbonaceous material, 190-193. Transcriber's Notes The following changes have been made to the text as printed. 1. Illustrations and end-of-page footnotes (marked with an asterisk) have been located in appropriate paragraph breaks. References, marked with numbered indices, have been re-indexed and are listed at the end of each chapter as in the book. 2. Obvious typographical errors have been corrected. 3. Where a word is used repeatedly in the same way, spelling and hyphenation have been made consistent, preferring the form most often used in the printed work, or failing that the more usual form in general use at the time of publication. No typographical change has been made within direct quotes from other works. 4. Page 25: "or thoradico-lumbar division" has been changed to "or thoracico-lumbar division". 5. Page 58: The name "Emden" in "Emden and v. Furth" has been changed to "Embden" in agreement with Footnote 1 on Page 65. (Gustav Embden, 1874-1933.) 6. Page 62: The Greek letter Β (Beta) has been substituted for Latin B at the start of "Β-tetrahydronaphthylamine".