Hydrogen embrittlement of steels is hardly a new subject, but the effects of high-pressure hydrogen have been treated in detail only more recently and to a much more limited extent. Thus, most investigations of hydrogen embrittlement have been concerned with hydrogen in metals, while for the high-pressure hydrogen problem, we are more concerned with metals in(in contact with) hydrogen. I believe there is a difference and, certainly,different mechanisms of embrittlement are at least possible.; Presented at the Central Florid Section, American Welding Society, Orlando, Florida, 14 November 1967 and North Alabama Chapter, American Society for Metals, Huntsville, Alabama, 16 November 1967.