Just found this website so a little late with entering the discussion...
A few years ago, Swim wanted to try the Mescaline (after reading Huxley's "Doors of Perception)> He tried the acid/base/solvent/re-crystalisation technique from San Pedro but got gelatinous mess (elogantly referred to as "Cactus Snot" on another site)'
He decided to try a methanol extraction from dried san pedro, consuming the unpurifed extract after the methanol evaporated.
It was certainly physcoactive at the published levels -200mg of green gunk gave quite a solid punch lasting a good seven to 8 hours - but the effects were no what he had expected (nothing like LSD, and nothing like Huxley had described). The body load was pretty terrible too with high BP and pulse, probably arrythmia too.
Somewhat put SWIM off, but recently SWIM had been pondering another shot at a crude extraction and was wondering along the lines:
dried San Pedro blended in methanol (or ethanol,
basify with NaOH, mild heat/reflux for an hour or two,
let methanol evaporate
Presumably the gunk remaining should contain as much mescaline as can be extracted by any method? (As well as other alkaloids, plant matter and sodium hydroxide)
wash the "gunk" repeatedly with cold water to remove excess hydroxide (shouldn't the mescaline remain as freebase and be insoluble in cold water?)
Would what remains contain the mescaline(?) and might it be possible to form impure crystals by dissolving directly in weak HCL or H2SO4 without performing any other steps?
SWIM is wishing to avoid not only the Cactus Snot Syndrome, but also the use of solvents if possible, while also removing at least some of the other matter that may have caused an unpleasant trip on his first attempt.
Any comments appreciated