The character of "Professor Meiklejohn," correct in the opening credits, is listed as "Professor Mendelssohn" in the closing credits.
At the end: "A Universal Cast is Worth Repeating." This credit appeared on many Universal films of that era, not just "The Invisible Ray", but it doesn't appear on the cast list for the 1936 "Show Boat", which Universal also made.
FOREWORD Every scientific fact accepted today once burned as a fantastic fire in the mind of someone called mad. Who are we on this youngest and smallest of planets to say that the INVISIBLE RAY is impossible to science? That which you are now to see is a theory whispered in the cloisters of science. Tomorrow these theories may startle the universe as a fact.