I can only presume, based on timing of the talk being 1960, that his thoughts here link to mescaline and the practical utopia he talks of in Island, whose inhabitants make use of a local psychedelic. So whatever he must have said here had more to do with his later perspectives than his feelings around the island.
> ... I have talked to pharmacologists about this matter, and a number of them say that it’s probably quite possible that it may be possible to, by pharmacological means, which will do no harm to the organism as a whole, to increase the span of attention, to increase the powers of concentration, perhaps to cut down on the necessity for sleep, and the various other things which may lead to a very considerable increase in general mental efficiency.
https://www.organism.earth/library/document/realizing-human-...
It turns out to refer to a drug in fiction which is named after the Vedic ritual drink.
Original Vedic "soma" is indeed more like a drink of inspiration and ecstasy, with myths similar to the norse "Mead of poetry".
"somasya tA mada indraS cakAra" - "In the exhilaration of soma, Indra has done these great deeds" - is a rig-vedic refrain.