The following is a short, somewhat clinical description of the effects of ingesting mescaline and related alkaloids. Much more colorful and enlightening accounts of the travels of Cactus psychonauts can be found in later chapters.

Mescaline is almost unique among drugs in that it works primarily on the visual areas of the cortex. The largest part of the mescaline experience is visual, including among other things, hallucinations.

After being absorbed by the bloodstream, mescaline has a half-life in the body of around 6 hours. Peak concentrations of mescaline occurs about 2 hours after oral administration, this corresponds to the time period of highest psychedelic effect. Drug levels in the blood drop gradually over 10 hours, with 87% of the dose eliminated after 24 hours.

Repeated, closely spaced use can produce a tolerance to mescaline's physiological, subjective and psychological effects. Repeated use over a 3 - 6 day period does lead to significant tolerance in man. Cross-tolerance to LSD and psilocybin has been demonstrated. Mescaline tolerance does not lead to physiological dependance like opoids, or alcohol.

Subjective effects - Introspective experiences, emotional lability, significant mood changes, and unprovoked emotional discharges are rather common. An increased perception of truth, a grasp of reality that one has never had before, is widely reported.

Physiological - Mescaline has been shown to impair complex discrimination tasks, problem solving and immediate memory. This may be due to a disinterest on the part of the subject, not because of the drug state.

Psychological - There are many reports of individuals, while at the peak of their experience, refusing to engage in routine psychological tasks because they felt that they were absurd. While in their elevated state, some subjects go into long fits of laughter when asked to do such things as putting different shaped objects into holes, or filling out questionnaires.

An interesting effect is that many subjects had a high ambivalence score on their Subjective Drug Effects Questionnaire. They reported feeling happy and unpleasant, or very sober and giddy at the same time. This phenomenon seems to be apparent in at least several of the hallucinogens, notably psilocybin. It is the duality of perception, a disconcerting effect where opposing feelings and emotions can occur simultaneously.

Set and Setting are probably the two most influential and critical factors that will determine the direction and quality of the ensuing experience.

Set refers to the psychological makeup of the person taking the hallucinogens. Such factors as personality, mood and expectations are all critically important in determining what type of reaction will ensue. What you have been thinking about, fretting over, or worrying about for the last few days, will likely appear again during your trip. This is usually not a good thing. Be calm, clear your mind of negative thoughts. As Monty Python so aptly said during one of their movies " always look on the bright side of life."

Setting refers to physical, emotional and social environment that the tripper will be exposed to during their journey. It is very possible to alter the direction of a trip from psychotic to psychedelic by simply manipulating lighting, music, those in the room, etc. The experience one receives will be quite different for instance, for a person experimenting the first time in unfamiliar surroundings among a group of people that the subject may not entirely trust, to being with your lover, watching the sunset from the back porch of a Malibu cabin.

The visual hallucinations described by most subjects are strikingly similar. Most report several different type, or form of image, such as:

A. Lattice work, grating, fretwork, filigree, honeycomb, or chessboard type of design.

B. Tunnel, funnel, tube, cone, alley or vessel.

C. Spiral patterns either simple or complex.

D. Cobweb type designs.

The thinness, or fineness of the lines that make up the observed patterns is also widely reported as one of the more interesting visual phenomenon.

There are also very noticeable auditory affects. Peyote brings on a sort of synesthesia, a mixing and interaction of the five senses. Peyotists often hear things directly from the Cactus. The Indians are quite certain that the Peyote provides them with their songs.

The following is a time frame, sequence of events that express on average, the effects felt after a moderate dose of mescaline. Remember, different physical and emotional make-ups will affect both the timing, and the effects that will be experienced.

30 minutes - The first effects will be noticed around this time. Minor perceptual changes, a feeling of strange intoxication, slight dizziness, shifts of consciousness. Some nausea or muscle tension may be felt. If you feel like you have to throw up, go ahead, most people feel much better afterwards, and it tends to give the trip a little kick-start.

60 minutes - The strong physical effects start to subside. A state of altered consciousness begins to unfold. A feeling of peace and contentment is also usually present. An amphetamine like stimulation is felt, coupled with feelings of fatigue and restlessness.

90 minutes - Most effects are beginning to peak at this point. The plateau is wide and long lasting, hard to tell when it begins or ends. Intense visuals begin.

120 minutes - An increase in emotional sensitivity, or empathy is present. Emotional inhibition is also very prevalent at this stage. 6 - 12 hours - The effects will gradually begin to wear off during this time period. It is usually difficult to sleep for at least 12 hours after ingestion, due to the fact that the constituent alkaloids are metabolized and excreted at different rates.

12 hours on - After glow. The explorer is very likely to feel pleasantly relaxed and refreshed, and having the calm sensation of being at Peace with the World. You will most probably be quite hungry after your journey.

The effects of ingesting San Pedro is somewhat different than with Peyote. The different alkaloids present alter the experience and produce a more mellow, warmer trip. The trip has been described as follows:

"The first noticeable effect is a slight dizziness, not at all disorienting like alcohol, but a barely perceptible lightness. And then, as if hit by a gust of wind, a great vision, a sharpening of the senses, a precise, crystal clearness of thought. A slowly spreading numbness flows through your body, a feeling of tranquility, so rare a treat in ones busy life. Next comes an eerie sort of detachment from our predictable, casual world. A visual force, a power, overwhelms us. All of our senses: seeing, hearing, tasting, smelling, touching, are linked to the others. A flood of perceptions being sucked in, through our eyes. One develops a sort of telepathic sense, the ability to transcend time, distance and space, simply by envisioning it. The ability to discern and analyze every problem, and the lucidity to overcome it."