I don't like being one of the people to say search through the forums, but in this case it is very true. Peyote is a cactus. Cacti alkaloids can easily be extracted. Separating the mescaline from the other alkaloids is very common. One just keeps the "wash," instead of throwing it away. Basic chemistry knowledge would help. Google, erowid, and wikipedia are awesome sources.
Posts made by me are either fictional or false, or both. I do not endorse, condone or engage in illegal activities. I love the state, my big brother. "I" myself am fictional. I am a collection of individuals, that are not entirely human. "I" do not exist in reality. Any resemblance to an individual bound by laws is merely coincidental. I lie and tell very little of the truth; do not believe me, and, especially, don't hold "me" accountable for any posts.