Both psychedelic compounds are alkaloids, so why I've to basify firstly, when extracting mescaline and to acify in the DMT-extraction firstly?

Mescaline, Cacti:
forums.mycotopia.net/mescaline-cacti-succulents/7933-mescaline-extraction-tek.html

DMT, Mimosa Hostilis:
wiki.dmt-nexus.me/w/images/0/09/The_DMT_Handbook_201208.pdf

Questions on the caci extraction:
- Is it also possible to use naptha in the mescaline extraction, because it's less harmful and more easy to get?
- Evaporating step: If acified water evaporates, does the PH drop or do the molecules which make it acid evaporate completely? (I think so, but I'm not shure.)
- Is there a reason, that the recrystallisation is done with another solvent (Aceton vs. Xylene)?

Feel free to promote me, I want to post in the specific sub forums and I will dedicate my first extraction to you...

It just depends on the type of tek you're doing. There are STB (straight to base) and A/B (acid/base) teks for both cacti and MHRB. Just read around this site or check out the wiki.

For cactus extraction I highly recommend 69ron's Mescaline Extraction.