|Summary sheet: Psilocin|
|Molecular structure of 4-HO-DMT|
|Common names||Psilocin, Psilocine, Psilocyn, Psilotsin, 4-HO-DMT, 4-OH-DMT|
|Routes of Administration|
4-Hydroxy-N,N-dimethyltryptamine (commonly known as Psilocin, Psilocine, Psilocyn, Psilotsin, or abbreviated as 4-HO-DMT and 4-OH-DMT) is a naturally-occurring psychedelic substance of the tryptamine chemical class that produces what are now typically considered to be "classical psychedelic" effects (i.e. those associated with LSD, Mescaline, Psilocybin and DMT) when administered. It is known as the primary psychoactive constituent in certain species of psilocybin-containing mushrooms, and as a closely related structural analog of the powerful visionary entheogen DMT (also known as N,N-dimethyltryptamine), which it shares many core subjective features with.
Psilocin and its phosphorylated inactive precursor (i.e. prodrug) psilocybin were first isolated and named in 1958 by Swiss chemist Albert Hofmann. Hofmann obtained the chemicals from laboratory-grown specimens of the entheogenic mushroom Psilocybe mexicana before proceeding to find their synthetic routes. Psilocin's psychoactivity is thought to emerge from the close structural similarities that it shares on a molecular level with serotonin (5-hydroxy-trypamine), which enables it to interact with a wide range of serotonin receptor sites distributed throughout the brain and central nervous system that are integral for sensory input processing and higher-order cognitive processes. It is believed to exert most of its characteristic psychedelic activity by binding to serotonin-2A or 5-HT-2A receptors with an atypically high degree of selectivity (please see this page for more information).
Notably, while psilocin naturally co-occurs with psilocybin in significant amounts of most psychedelic or psilocybin-containing mushrooms, it is only ever rarely encountered in its isolated synthetic form. Those who have had the opportunity to experiment with synthetic psilocin powder have reported it to be a powerful, visionary substituted tryptamine with a deep, all-encompassing headspace, immersive visuals with high-level geometry, and a rapid challenging come up that is both reportedly more lucid and anxiety-provoking than orally ingested psilocybin mushrooms; this may make the experience overly intense for those who are not well versed with psychedelics.
As with psychedelics in general, psilocin is not considered to be addictive by the research and medical community. Nevertheless, unpredictable adverse reactions such as anxiety, paranoia, delusions and psychotic breaks can still always occur, particularly among those predisposed to psychiatric disorders. While these negative reactions or "bad trips" can often be attributed to factors like the inexperience or improper preparation of the user's set and setting, they have been known to happen spontaneously among even the most experienced of users as well. This is why despite its scientifically-backed reputation for possessing negligible toxicity, it is still highly advised to approach this potent, unpredictable, hallucinogenic substance with the proper amount of precaution and harm reduction practices if one chooses to use it.
- 1 Chemistry
- 2 Pharmacology
- 3 Subjective effects
- 4 Combinations
- 5 Potential therapeutic applications
- 6 Toxicity and harm potential
- 7 Legality
- 8 See also
- 9 External links
- 10 References
Psilocin, or 4-HO-DMT, is an organic indole alkaloid molecule of the tryptamine class of chemicals. Tryptamines share a core structure comprised of a bicyclic indole heterocycle attached at R3 to an amino group via an ethyl side chain. 4-HO-DMT is substituted at R4 of its indole heterocycle with an hydroxyl (-OH) functional group; it also contains two methyl groups CH3- bound to the terminal amine RN of the ethyl side chain. This makes psilocin the 4-hydroxy structural analog of DMT, and dephosphorylated analog of psilocybin.
Psilocin can be obtained by dephosphorylation of natural psilocybin under strongly acidic or under alkaline conditions via hydrolysis, which is how it becomes metabolically active in the human body as well.
In terms of its physical properties, 4-HO-DMT is relatively unstable in solution due to its phenolic hydroxy (-OH) group. In the presence of oxygen it readily forms bluish and dark black degradation products. For this reason it is recommended to store it in optimal chemical storage conditions (i.e. cool, dry, away from light) to avoid excessive degradation.
Psilocin's psychedelic effects are believed to come from its binding efficacy at the 5-HT2A receptor as a partial agonist. Unlike LSD, this compound has no significant effect on dopamine receptors and only affects the noradrenergic system at very high dosages. However, the role of these interactions and how they result in the psychedelic experience continues to remain elusive.
The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. The listed effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances and are more likely to induce a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include injury or death.
- Sedation - In terms of its effects on the physical energy levels of the tripper, psilocin is considered by most to be relaxing, stoning and mildly sedating. This sense of sedation is often accompanied by compulsive yawning.
- Perception of bodily heaviness - This effect corresponds with the general sense of sedation and relaxation that characterizes psilocin experiences, this manifests as a bodily heaviness that discourages movement but is typically only prominent during the first half of the trip. This particular physical effect seems to be more commonly experienced and pronounced with certain “woodlover” species of mushrooms such as Psilocybe azurescens.
- Spontaneous physical sensations - The "body high" of psilocin can be described as a pleasurable, soft and all-encompassing tingling sensation or glow. This maintains a consistent presence that steadily rises with the onset and hits its limit once the peak has been reached. Once the peak of the experience or sensation is reached it can feel incredibly euphoric and tranquil or heavy and immobilizing depending on the dose.
- Changes in felt bodily form - This effect is often accompanied by a sense of warmth or unity and usually occurs around the peak of the experience or directly after. Users can feel as if they are physically part of or conjoined with other objects. This is usually reported as feeling comfortable in its sensations and even peaceful.
- Tactile enhancement - This effect is less prominent than with that of LSD or 2C-B but is still present and unique in its character. It is repeatedly described as feeling very primitive in its nature often times with the small hairs on the users arms or legs feeling slightly itchy or even ticklish against the skin.
- Changes in felt gravity
- Nausea - This effect can be greatly lessened or even completely avoided if the individual has an empty stomach prior to ingestion. It is often recommended that one either refrain from eating for approximately 6 to 8 hours beforehand, or eat a light meal 3 to 4 hours before if they are feeling physically fatigued. In the rare circumstances that pure psilocin is ingested this effect is considered to be much less prominent than it is with psilocybin mushrooms.
- Excessive yawning - This effect seems to be uniquely pronounced among psilocin and related tryptamines. It can occur to a lesser degree on LSD and very rarely on psychedelic phenethylamines like mescaline. It typically occurs in combination with watery eyes.
- Brain zaps - Although this effect is very rare, it can still occur for those susceptible to it. This component is however much less common and intense than it is with serotonin releasing agents such as MDMA.
- Watery eyes
- Muscle contractions
- Olfactory hallucinations
- Frequent urination
- Pupil dilation
- Runny nose
- Seizure - This is a rare effect but can happen in those predisposed to them, especially while in physically taxing conditions such as being dehydrated, undernourished, or fatigued.
- Sedation - In terms of its effects on the physical energy levels of the tripper, psilocin is considered by most to be relaxing, stoning and mildly sedating. This sense of sedation is often accompanied by compulsive yawning.
- Colour enhancement - In comparison to other psychedelics, this effect may appear to be more saturated.
- Visual acuity enhancement - This effect typically occurs at lower to medium doses and becomes increasingly suppressed at higher doses.
- Pattern recognition enhancement
- Drifting (melting, flowing, breathing and morphing) - In comparison to other psychedelics, this effect can be described as highly detailed, realistic, slow and smooth in motion and static in appearance.
- Colour shifting
- Colour tinting
- Visual haze
- After images
- Symmetrical texture repetition
- Perspective distortions
- Depth perception distortions
- Environmental orbism
- Scenery slicing
- Environmental geometry
The visual geometry that is present throughout this trip can be described as more similar in appearance to that of 4-AcO-DMT, ayahuasca and 2C-E than LSD or 2C-B. It can be comprehensively described through its variations as intricate in complexity, abstract in form, organic in feel, structured in organization, brightly lit, and multicoloured in scheme, glossy in shading, soft in its edges, large in size, slow in speed, smooth in motion, rounded in its corners, non-immersive in-depth and consistent in intensity. It has a very "organic" feel and at higher dosages is significantly more likely to result in states of Level 8B visual geometry over level 8A.
Psilocin and its various other forms produce a full range of high level hallucinatory states in a fashion that is more consistent and reproducible than that of many other commonly used psychedelics. These effects generally include:
- Internal hallucinations (autonomous entities; settings, sceneries, and landscapes; alterations in perspective and scenarios and plots) - This effect is very consistent in dark environments at appropriately high dosages. They can be comprehensively described through their variations as lucid in believability, interactive in style, new experiences in content, autonomous in controllability, geometry-based in style and almost exclusively of a personal, religious, spiritual, science-fiction, fantasy, surreal, nonsensical, or transcendental nature in their overall theme.
- External hallucinations (autonomous entities; settings, sceneries, and landscapes; alterations in perspective and scenarios and plots) - These are more common within dark environments and can be comprehensively described through their variations as lucid in believability, interactive in style, new experiences in content, autonomous in controllability, geometry-based in style and almost exclusively of a personal, religious, spiritual, science-fiction, fantasy, surreal, nonsensical or transcendental nature in their overall theme.
- Shadow people
The cognitive effects of psilocin are described by many as extremely relaxing, profound and stoning in style when compared to other commonly used psychedelics such as LSD or 2C-B which tend to be energetic and stimulating, it is also regarded as being notably more lucid than psilocybin mushrooms but not as clearheaded as DMT. It contains a large number of both typical and unique psychedelic cognitive effects.
The most prominent of these typical effects generally include:
- Enhancement and suppression cycles - This can be described as constant waves of extremely stimulated and profound thinking which are spontaneously surpassed in a cyclic fashion by waves of general thought suppression and mental intoxication. These two states seem to switch between each other in a consistent loop once every 20 to 60 minutes.
- Emotionality enhancement - This effect can be described as being more prominent, consistent and profound when compared to other traditional psychedelics such as mescaline or LSD. This can lead to strong feelings of compassion, urgency and even completely sporadic moments of intense emotional significance that can also be periodically affected by enhancement and suppression cycles.
- Empathy, affection, and sociability enhancement - This effect differs from MDMA and other entactogens in that it isn't as central to the experience, feels less forced and more natural and is experienced at a less consistent rate. The sociability enhancement in particular only occurs rarely and it appears to be more emotional.
- Simultaneous emotions
- Language suppression - This effect can be described as a perceived inability or general unwillingness to talk aloud despite feeling perfectly capable of formulating coherent thoughts within one's internal narrative. It is much more common among inexperienced users.
- Subconscious communication
- Cognitive euphoria
- Analysis enhancement - This effect is consistent in its manifestation and outrospection dominant.
- Conceptual thinking
- Personal bias suppression
- Novelty enhancement
- Immersion enhancement
- Creativity enhancement
- Feelings of impending doom - This effect is usually only experienced during the come up phase but typically completely passes or subsides once the primary effects begin. It should be noted that this effect is relatively consistent and normal for psilocin and related tryptamines which is why a positive and well-informed mindset is key. Less regularly this aspect can also occur during the peak but will most often be met after with sensations of euphoria or rejuvenation.
- Catharsis - While this component can occur spontaneously, it typically follows a difficult phase of the experience, if not the entirety of the experience itself.
- Rejuvenation- While this component can occur spontaneously at any point, it typically follows a difficult phase of the experience, if not the entire experience itself. It is however almost always felt during the offset of a psilocin trip and tends to slowly transition into the after effects which are generally described as positive. These positive or mindful after effects are sometimes referred to as an "afterglow" and is both common and consistent for psilocin and related tryptamines.
- Memory suppression
- Addiction suppression
- Thought connectivity
- Thought deceleration
- Thought organization
- Confusion - This effect is commonly reported to occur at a higher rate than with other psychedelics such as LSD or mescaline. It is more commonly observed in users who are generally inexperienced with psychedelics.
- Déjà vu
- Increased music appreciation
- Increased sense of humor
- Ego replacement - Although this effect is rare and more likely to occur with certain psychedelics like DMT or ayahuasca, it can still occur with high dosages.
- Personality regression - While this effect is not typically observed, it can still spontaneously manifest and is thought to depend primarily on the user's set and setting.
- Time distortion
- Synaesthesia - In its fullest manifestation, this is a very rare and non-reproducible effect. Increasing the dosage can increase the likelihood of this occurring, but seems to only be a prominent part of the experience among those who are already predisposed to synaesthetic states.
- Dosage independent intensity
- Anecdotally, components such as these are generally considered to be most consistent with the naturally occurring entheogenic tryptamines such as ayahuasca, ibogaine and psilocybin/psilocin.
Anecdotal reports which describe the effects of this compound within our experience index include:
Additional experience reports can be found here:
- Cannabis - When used in conjunction with cannabis, both the visual and cognitive effects of psilocin can be intensified and extended with extreme efficiency. This should be used with extreme caution, especially if one is not experienced with psychedelics. This interaction can also amplify the anxiety, confusion and psychotomimetic producing aspects of cannabis significantly. The THC and psilocin synergy is unique in that the severity of its mind-altering qualities can greatly depend on when during the trip the cannabis is taken, as psilocin experiences are often considered to have less continuity than many other commonly used psychedelics.
- Dissociatives - When used in combination with dissociatives, the geometry, euphoria, dissociation and hallucinatory effects are often greatly enhanced. Dissociative-induced holes, spaces, and voids while under the influence of psilocin can result in significantly more vivid visuals than dissociatives alone present, along with more intense internal hallucinations, confusion, nausea, delusions and chances of a psychotic reaction.
- MDMA - When used in conjunction with MDMA, the physical and cognitive effects of MDMA are amplified. The visual, physical and cognitive effects of psilocin are also intensified with an overwhelming euphoric bliss manifested through uniquely pleasurable body highs and headspaces, and uniquely colorful, intricate and majestic visuals. The synergy between these substances is unpredictable, and it is best to start with lower dosages than one would take for both substances individually.
- Alcohol - This interaction is not typically recommended due to alcohol’s ability to cause dehydration, depression, nausea and thought disorganization which can negatively affect a trip if taken in high dosages. This combination is however reasonably safe in low doses and when used responsibly, this can often take the edge off a trip as well as dull its psychedelic effects in a fashion somewhat similar to benzodiazepines, it is, however, more stressful on the body. With psilocybin mushrooms in particular it is often recommended that the user wait until the come down before they indulge in the consumption of alcohol due to the sometimes already nauseating and lumbering physical effects of mushrooms, especially within the first 2 - 3 hours of the trip. With pure psilocin these physical effects can appear to be less intense but are still generally not recommended due to the infamously unpredictable and purportedly even perilous nature of the psilocin and ethanol synergy. It also is worth noting that experiencing psilocybin/psilocin while feeling the after effects of alcohol can present substantially negative psychological reactions and a significant risk for bad trips that is uniquely higher with psilocin than it is with other common psychedelics.
- Benzodiazepines - When used in combination with benzodiazepines, benzodiazepines can, depending on the dosage, slightly to completely reduce the intensity of the cognitive, physical and visual effects of a psilocin trip. They can be very efficient at largely stopping or mitigating a bad trip at the cost of amnesia and reduced trip intensity. Caution is advised when acquiring them for this purpose, however, due to the very high addiction potential that benzodiazepines possess.
Potential therapeutic applications
While further research is needed to establish the utility of psilocybin and other psychedelics in treating depression, a pilot study has observed significantly decreased depression scores in terminal cancer patients six months after treatment with psilocybin. An open-label study was carried out in 2016 in the UK to investigate the feasibility, safety and efficacy of psilocybin in treating patients with unipolar treatment-resistant depression with promising results; although the study was small and involved only twelve patients, seven of those patients met formal criteria for remission one week following psilocybin treatment and five of those were still in remission from their depression at three months.
The mechanism behind this is not known as of yet, but researchers have suggested that psilocin's deactivation of the medial prefrontal cortex (mPFC) may be relevant to its antidepressant effects, as the mPFC is known to be elevated in depression and normalized after effective treatment. mPFC hyperactivity has been associated with trait rumination. Another possible factor to psilocybin's potential against depression may be that depressed patients with high levels of dysfunctional attitudes were found to have low levels of 5-HT(2A) agonism.
Toxicity and harm potential
Psilocin is non-addictive, is not known to cause brain damage, and has an extremely low toxicity relative to dose. Similar to other psychedelic drugs, there are relatively few physical side effects associated with acute psilocin exposure. Various studies have shown that in reasonable doses in a careful context, it presents little to no negative cognitive, psychiatric or toxic physical consequences.
The toxicity of psilocybin and psilocin is extremely low. In rats, the median lethal dose (LD50) of psilocybin when administered orally is 280 milligrams per kilogram (mg/kg). Psilocybin comprises approximately 1% of the weight of Psilocybe cubensis mushrooms and so nearly 1.7 kilograms (3.7 lb) of dried mushrooms or 17 kilograms (37 lb) of fresh mushrooms would be required for a 60 kilogram (130 lb) person to reach the 280 mg/kg LD50 value of rats. Based on the results of animal studies, the lethal dose of psilocybin has been extrapolated to be 6 grams, 1000 times greater than the effective dose of 6 milligrams.
Despite its lack of physical toxicity, however, it is still strongly recommended that one use harm reduction practices if choosing to use this substance.
Tolerance and addiction potential
Psilocin is not habit-forming and the desire to use it can actually decrease with use. It is most often self-regulating.
Tolerance to the effects of psilocin are built almost immediately after ingestion. After that, it takes about 3 days for the tolerance to be reduced to half and 7 days to be back at baseline (in the absence of further consumption). Psilocin presents cross-tolerance with all psychedelics, meaning that after the consumption of psilocin all psychedelics will have a reduced effect.
This legality section is a stub.
As such, it may contain incomplete or wrong information. You can help by expanding it.
Psilocin is a Schedule I drug under the Convention on Psychotropic Substances, meaning the possession and sale of it (including psilocin and psilocybin-containing mushrooms) is prohibited in most countries.
- Brazil - Possession, production and sale is illegal as it is listed on Portaria SVS/MS nº 344, but mushrooms fall under religious use laws.
- British Virgin Isles: The sale of mushrooms is illegal, but possession and consumption is legal.
- Bulgaria: The sale of mushrooms is illegal, but possession and consumption is legal.
- Belgium: Possession and sale of mushrooms have been illegal since 1988.
- Canada: Psilocybin and psilocin are illegal to possess, obtain or produce without a prescription or license as they are Schedule III under the Controlled Drugs and Substances Act.
- Czech Republic: The distribution (including sale) of mushrooms is illegal, but consumption is legal. The possession of over 40 hallucinogenic caps is considered a crime if they contain more than 50mg of psilocin or the corresponding amount of psilocybin. The possession of more than 40g of hallucinogenic mycelium is considered a crime. If these limits are not exceeded, the act is considered a minor offence and a fine of up to 15 thousand CZK may be imposed.
- Cyprus The possession, sale and consumption of mushrooms is illegal.
- Denmark: The possession, growth, sale and consumption of mushrooms is illegal.
- Finland: The possession, growth, sale and consumption of mushrooms is illegal.
- Germany: The possession, growth, sale and consumption of mushrooms is illegal.
- Greece: The possession, growth, sale and consumption of mushrooms is illegal.
- Ireland: The possession, growth, sale and consumption of mushrooms is illegal.
- Japan: The possession, growth, sale and consumption of mushrooms is illegal.
- Latvia: Hallucinogenic mushrooms, psilocin and psilocibyn are Schedule I controlled substances.
- Mexico: The possession, growth, sale and consumption of mushrooms is illegal. Rules are relaxed regarding religious use however.
- The Netherlands: The possession, growth, sale and consumption of mushrooms is illegal. However, due to a legal loophole, psilocybin truffles can be legally possessed, grown, sold and consumed.
- New Zealand: Psilocybin is Class A.
- Norway: Possession, growth, sale and consumption of mushrooms is illegal. Spores, even though not containing psilocybin, are also illegal.
- Turkey: The possession, growth, sale and consumption of mushrooms is illegal.
- UK: According to the 2005 Drugs Act, fresh and prepared psilocybin mushrooms are Class A.
- USA: Psilocybin and psilocin are illegal Schedule I drugs.
- Responsible use
- Psilacetin (4-AcO-DMT)
- Metocin (4-HO-MET)
- Psilocybin & Psilocin (Erowid)
- Psilocin (Wikipedia)
- Psilocin (TiHKAL)
- The Big & Dandy Psilocybin Mushrooms Thread (Bluelight)
- Psilocybin mushrooms (Disregard Everything I Say)
- World Wide Distribution of Magic Mushrooms
- Hofmann, A., Heim, R., Brack, A., Kobel, H., Frey, A., Ott, H., Petrzilka, Th. and Troxler, F. (1959), Psilocybin und Psilocin, zwei psychotrope Wirkstoffe aus mexikanischen Rauschpilzen. HCA, 42: 1557–1572. https://doi.org/10.1002/hlca.19590420518
- Lüscher, C., & Ungless, M. A. (2006). The Mechanistic Classification of Addictive Drugs, 3(11). https://doi.org/10.1371/journal.pmed.0030437
- Strassman, R. J. (1984). Adverse Reactions to Psychedelic Drugs: A Review of the Literature. The Journal of Nervous and Mental Disease, 172(10), 577-595. PMID: 6384428
- Nichols, D. E. (2016). "Psychedelics." Pharmacological Reviews, 68(2), 264-355. https://doi.org/10.1124/pr.115.011478
- Petri, G., Expert, P., Turkheimer, F., Nutt, D., Hellyer, P. J., & Vaccarino, F. (2014). Homological scaffolds of brain functional networks, 14–18. https://doi.org/10.1038/nrn2618
- Psilocybin Investigator’s Brochure | http://www.maps.org/research/psilo/psilo_ib.pdf
- Johnson, M. W., Garcia-Romeu, A., Cosimano, M. P., & Griffiths, R. R. (2014). Pilot study of the 5-HT2AR agonist psilocybin in the treatment of tobacco addiction. Journal of Psychopharmacology, 28(11), 983-992. https://doi.org/10.1177/0269881114548296
- Grob, C. S., Danforth, A. L., Chopra, G. S., Hagerty, M., McKay, C. R., Halberstadt, A. L., & Greer, G. R. (2011). Pilot study of psilocybin treatment for anxiety in patients with advanced-stage cancer. Archives of General Psychiatry, 68(1), 71-78. https://doi.org/10.1001/archgenpsychiatry.2010.116
- Carhart-Harris, R. L., Bolstridge, M., Rucker, J., Day, C. M., Erritzoe, D., Kaelen, M., ... & Taylor, D. (2016). Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study. The Lancet Psychiatry, 3(7), 619-627. https://doi.org/10.1016/S2215-0366(16)30065
- Carhart-Harris, R. L., Erritzoe, D., Williams, T., Stone, J. M., Reed, L. J., Colasanti, A., ... & Hobden, P. (2012). Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin. Proceedings of the National Academy of Sciences, 109(6), 2138-2143. https://doi.org/10.1073/pnas.1119598109
- Farb, N. A. S., Anderson, A. K., Bloch, R. T., & Segal, Z. V. (2011). Mood Linked Responses in Medial Prefrontal Cortex Predict Relapse in Patients with Recurrent Unipolar Depression. Biological Psychiatry, 70(4), 366–372. https://doi.org/10.1016/j.biopsych.2011.03.009
- Bhagwagar, Z., Hinz, R., Taylor, M., Fancy, S., Cowen, P., & Grasby, P. (2006). Increased 5-HT 2A receptor binding in euthymic, medication-free patients recovered from depression: a positron emission study with [11 C] MDL 100,907. American Journal of Psychiatry, 163(9), 1580-1587. http://dx.doi.org/10.1176/ajp.2006.163.9.1580
- Meyer, J. H., McMain, S., Kennedy, S. H., Korman, L., Brown, G. M., DaSilva, J. N., ... & Houle, S. (2003). Dysfunctional attitudes and 5-HT2 receptors during depression and self-harm. American Journal of Psychiatry, 160(1), 90-99. https://www.doi.org/10.1176/appi.ajp.160.1.90
- "Green list" (PDF). INCB. Retrieved 2017-10-11.
- Controlled Drugs and Substances Act of Canada
- Noteikumi par Latvijā kontrolējamajām narkotiskajām vielām, psihotropajām vielām un prekursoriem (I saraksts) | http://likumi.lv/doc.php?id=121086
- Legislation - Drugs Act 2005| http://www.legislation.gov.uk/ukpga/2005/17/contents
- FDA - Controlled Substances Act| http://www.fda.gov/regulatoryinformation/legislation/ucm148726.htm