The link (including the transcript of Huxley’s lecture) doesn’t seem to be about Soma, unless I’m missing something. Huxley produced a lot of work outside of Brave New World, lots of it concerned with drugs and altered states of consciousness (so much so that personally I don’t think I’ve done enough drugs to understand his perspective, as I find him distinctly, and almost uniquely among such high-profile authors that I’ve tried, unreadable)