-By Marcel Granier-Doyeux, M.D, Ph.B.
From very remote times, the indigenous inabitants of various parts of South America have been aware of the hallucinogenic properties of diverse species of the genus Piptadenia. The purpose of the present study is to bring out the salient facts concerning this botanical genus, which are of special importance today when pharmacotoxicology has reached what might be called the epoch of the “psychopharmacos .”
In the Caribbean Islands and in South America, piptadenias are known by various popular names, such as cebil, coboba, cohoba, cojoba, curupa, curuva, hataj, kurupa, kurupayara, niopo, nupa, nopo, parica, vilca, yopo, yupa.
Historical and ethnographic data
Evidence of the use of Piptadenias exists from the time of the arrival of Christopher Columbus in the New World. The geographical area in which these plants are found embraces the West Indies, Brazil, Venezuela, Peru, Chile, Paraguay and the northern and central parts of Argentina. Throughout this vast zone the aborigines were familiar with the properties of Piptadenias, of which they made use by inhaling the powder obtained from the seeds. The variety of names which they bestowed on this plant can be gathered from the synonyms listed in the preceding paragraph.
Fray Bartolomé de Las Casas, in the course of a very detailed account of cohoba, states that the natives used to hold meetings during which the chief inhaled powder made from the seeds. These meetings took place when matters of special importance to the tribe had to be discussed (De Las Casas 1958).
Francisco Lopez de Gomara noted the same custom among the aborigines of Hispaniola where the bohitis (witch-doctors) also made use of the therapeutic properties of the powder (De Gomara 1552).
Sotelo Narvaez , in 1583, was probably the first person to describe the way in which the Comechingon Indians living in the Cordoba Mountains used powder made from cebil seeds (Narvaez 1583).
“El Orinoco Ilustrado” (The Orinoco Illustrated) by Padre José Gumilla contains the following passage on the Otomac Indians:
“… They have another dreadful way of getting drunk through the nose, using malignant powders called yupa, which drive them completely out of their minds so that, beside themselves, they seize any weapon to hand and if the women were not clever enough to stop them and tie them up, they would wreak cruel havoc every day: this is a terrible vice. They make these powders from the beans of the yupa plant, from which they get their name; by themselves they merely have the smell of strong tobacco; it is what is added to them by the work of the devil that causes the drunken fury. After eating some very big snails, which they find in the swamps they throw the shells into the fire and reduce them to quicklime, whiter than snow itself. They then mix this quicklime with the yupa, in equal quantities, and after grinding down the whole to a very fine powder, they obtain a mixture of such diabolical subtlety that the most hardened snuff-taker, so accustomed to tobacco that it no longer has any effect on him will, if he dips the tip of his finger in this powder and just puts his finger near to but without touching his nose, break out into a positive tempest of sneezing. The Saliva Indians and other tribes of whom I shall speak later, also take yupa; but as they are gentle, harmless and cowardly people, they do not become infuriated like the Otomacs who, for that very reason, have been, and still are, a terror to the Caribs, for they get fighting mad with yupa, wound themselves, and, full of blood and fury, go out to fight like raging tigers” (Gumilla 1741).
Fray Ramón Bueno referring in his “Treatise” to the trade in beads carried on by the Otomac Indians says:
“They have another equally profitable trade – viz. dealing in curuva or nopo with the Otomacs of Caracas province opposite. The tree does not grow in that province and at harvest time the Indians gather as much as they can and make it into medium-sized cakes, which they let the others have in exchange for shells, silver and glass beads, always keeping what they consider sufficient for their own use” (Bueno 1933).
Padre Juan Rivero in his history of the Missions in the Casanare plains and on the Orinoco and Meta Rivers, likewise makes numerous references to this trade.
In this text, the ancient orthograph has been respected in Spanish, and the paragraph from Father Gumilla’s work has been reproduced literally.
According to Padre Pane, the habit of inhaling powdered cohoba made the Indians so drunk that they would see their huts coming towards them and their companions walking with their feet in the air. When they became sober, they would relate what the Cemi (Great Spirits) had revealed, or announced to them (Flury 1958).
Many explorers of the American continent have referred to the use of nopo. One of the most famous, Baron Alexander von Humboldt, has given us in his travels an excellent description of this custom (Von Humbolt 1799).
In his work on the Guarani Indians, Bertoni speaks of the use made of kurupa, from the Amazon to Paraguay. The natives in this region were and still are in the habit of using powder made from the seeds of the tree known to them as kurupayara (Flury 1958). The Omagua Indians also used to take this drug, as de la Condamine observed:
“The Omaguas make considerable use of two kinds of plant: one, which the Spaniards call Floripondia, and the other, which is known in the Omagua tongue as curupa; both are purgatives. These peoples get drunk on these plants, the intoxication lasting twenty-four hours, and while under their influence they have very strange visions. They also take curupa in powdered form, as we take tobacco, but more ostentatiously. They use a hollow forked reed, in the shape of a letter Y, inserting each branch of the fork into one of the nostrils; this operation, followed by a violent intake of breath obliges them to make a grimace that seems very ridiculous in the eyes of Europeans, who like to compare everything with their own customs” (De La Condamine 1743).
Equally valuable data has been provided by the well-known Venezuelan writer Lisandro Alvarado (Alvarado 1945).
Among the many authors who have dealt with Piptadenias, mention should also be made of Boman (Flury 1958), Koch-Gruenberg (1909) and Padre Lozano (Flury 1958) who have described the usage among the Indians in Bolivia, Brazil and in the Orinoco zone.
For many years little interest was shown in this subject but, in 1948, we were consulted about the matter by the Pan-American Public Health Office. Our report on it was published in the Public Health Offices Bulletin. Later in the same year and subsequently, in 1956, we published further papers on the subject (Granier-Doyeux 1948).
Ethnographers who have studied the use of hataj include Elisabeth Dijour and Enrique Palavecinu, Director of the Tucuman Ethnographic Museum . Both authors have described ceremonies among the Bazan-Coronel Indians who resort to mass magic in order to drive away certain diseases, or implore help from the spirits. During these ceremonies the tribal witch-doctors inhale powder made from the seeds and scatter some of it on the ground for the spirits of the deceased witch-doctors invited to attend the functions. In his interesting study on the same topic, Lazaro Flury has related how on one occasion an El Pintado chief told him “The man seems to be flying “, thereby revealing the motory and psychic excitative effects of the drug (Flury 1958).
According to Pittier, the word niopo is current in South Venezuela, yopo in the Upper Orinoco area, and cojoba in North Venezuela and Haiti (Pittier 1926). Gumilla always uses the name yupa. According to Humboldt, the Otomac Indians called it niopo and in the Maypure dialect, nupa. The same author tells us that the missionaries knew it as nopo. As we have already seen Fray Ramon Bueno speaks of curuvaor nopo. The Guahibo Indians always call the drug yopo. The Mataco Indians call it hataj and the Guaranis, kurupa.
Willdenow classifies the plant as an Inga. This classification was disputed by Humboldt, who attributed it to an oversight on the part of Willdenow, with the result that in the work published by C. S. Kunth the plant appears as an Acacia. In this work, entitled ” Synopsis Plantarum Aequinoctialium Orbis Novi”, which contains all the plants studied by Humboldt and Bonpland in the New World, we find it described as follows:
32. Acacia NIOPO: A. inermis; foliis bipinnatis; pinnis sub 23-jugis; foliolis 50-70 jugis; linearibus, subfalcatis, acutis, obsolete uninerviis, membranaceis, glabris, ciliatis; glandula supra basim petioli et inter summum pinnarum par; leguminibus linearibus rostratis (Kunth 1839, 282).
Today the scientific name given to the plant is Piptadenia peregrina Benth. of the family Mimosaceae.
Pittier describes the plant in the following terms: “A medium-sized tree with most beautiful foliage, the leaves having from 15 to 30 pinnae, each bearing from 30 to 80 tiny leaflets; the flowers, in pedunculate capitula, are white; the legume is up to 15 cm. long and from 1.3 to 1.7 cm. wide. The wood is very hard, composed of knotty fibres and difficult to work. It is curious to find that this tree has the same native name of cojobaor cohoba in Haiti and in Venezuela, and that in both countries the aborigines were accustomed in the past, as they still are in parts of Venezuela and in the adjoining areas of Colombia and Brazil, to get drunk by inhaling the powder obtained from grinding its seeds, which provokes a kind of temporary madness” (Pittier 1926).
The above description may be supplemented by the observations of Llewellyn Williams in his “Exploraciones Botánicas en la Guayana Venezolana” :
“A tree 12 m. or more in height with a spreading tuft; the trunk is usually crooked, measures up to 35 cm. or more in diameter and is more or less free of branches till halfway up; the bark is thick and rough; the leaflets are tiny, linear and pinnated; the flowers, yellowish white in colour, form dense clusters; the legume reaches as much as 16 cm. long and is from 1.5 to 2 cm wide; the wood is hard and strong with dark duramen, but the dimensions are generally small and it is therefore of little practical use. The bark is rich in tanning principle. This tree abounds in scattered woodlands and on the savannas and the fringes of the jungle bordering the plains. Hataj or cebil has been given the scientific name of Piptadenia macrocarpa Benth (Williams 1942).
How the drug is obtained – Special preparation and mode of use
Baron Alexander von Humboldt has left us an account, which we give below, of the method of obtaining and preparing the drug attributed by him to the Otomac Indians.
“… They also reach a special state of drunkenness, which might be called madness, by using the niopo powder (in maypure, nupa), (the missionaries call it nopo). They collect the long shells of a species of mimosa to which we have given the name Acacia Niopo; they break them up, moisten them and leave them ferment. When the softened seeds begin to turn black, they knead them into a paste; after mixing this with yuca flour and lime obtained from the shells of a kind of Ampularia snail, they heat the dough over a very hot fire on a hardwood grid. The hardened dough is made into small cakes. Before the drug is taken, these are reduced to very fine powder and placed on a plate from 5″ to 6″ long. The Otomac Indian holds this plate, which has a handle, in his right hand while he breathes in the niopo through a forked bird’s bone, putting the ends in his nose. The bone, without which the Otomac would not think it possible to take this kind of snuff, is about 7″ long; it seemed to me to be the shank of a big wading-bird. I have sent some niopo and all this strange apparatus to Mr. de Fourcroy in Paris. Niopo is so stimulating that for anyone not used to it the smallest quantities provoke violent sneezing…” (Von Humbolt 1799).
“… Yopo or yupa is a kind of snuff extracted from the seeds of a species of Gwana acacia, also called yopo or niopo. The legumes are gathered, broken up, moistened and left to ferment” (Gumilla 1741).
Description of the use of nopo by the Guahibo Indians: At the present time, various Indian tribes still take nopo, a vice they have inherited from their forebears. The most usual procedure is as follows: the dried seeds of Piptadenia peregrina Benth are finely ground and the powder thus obtained is mixed with another produced by crushing the shells of a variety of snail, generally Ampularia. As reported by Humboldt, huca flour is certainly added, although some Indians maintain that banana flour is preferable. It is also said that the fat extracted from the snails is used for cooking the dough. After this cooking process, small cakes are made and these are pounded with a mortar on a special plate to provide the powder, which is inhaled like snuff. The wooden plate, shown in figure III, is flat and has a slightly raised rim; it is ovaloid in shape and measures 11 cm x 9.5 cm. It has a flat handle 5.5 cm long and about 1 cm thick, which is 6 cm wide where it joins the plate, and 10 cm wide at the farther end.
The mortar consists of two small tapered blocks joined at their smaller end. It is 5.5 cm long, 3 cm wide and 2.5 cm thick. Figures III and IV show all the implements used by the Guahibo Indians. The inhaler is made from a bone and appears in fact, to be a forked bone of a large wading-bird (probably a Jabiru); it is hollow and bound at the fork with waxed cord; the lower end, to be immersed in the powder, is bevelled; the upper ends are tipped with small perforated balls (two dried berries) which are applied to the nasal orifices. A bird’s feather is used to keep the inhaling tube clear. The powder, prepared as described above, is of a reddish-brown colour, thick and a strong irritant.
All this arsenal of equipment is carried about in a small basket made of woven palm leaves.
Description of the use of nopo by the Guaica Indians: The methods used for inhaling the drug vary with the region. For example, the Guaica Indians do not use the same implements as those described above. These natives use a long tube, the farther end of which is inserted in the nostril of the Indian who is going to inhale the powder, while an assistant applies his mouth to the other end and blows the powder vigorously through the tube.
Use of the drug by Yabarana Indians: In an excellent study of the Yabarana Indians, Johannes Wilbert has also described the way members of this tribe take powdered Piptadenia. According to this author, the Yabarana Indians use the same methods as the Guahibos, described above (Wilbert 1959).
Data concerning the chemical composition of the drug
The chemical analysis of the plant has been carried out by Fisch, Johnson, and Homing. These scientists have studied the composition of the seeds and legumes (pods) of two species, Piptadenia peregrina Benth, and Piptadenia macrocarpa Benth.
The seeds and pods of both species were found to contain 4 indole bases. The pods contain N.N-dimethyltryptamine and the seeds bufotenin, bufotenin oxide and oxide of N.N.-dimethyltryptamine.
The seeds of the species macrospora were also found to contain a 5-hydroxyindole base of unknown structure.
The above-mentioned researchers identified these components, isolating them by paper chromatography and comparing them with test samples covering data relating to the Rf, the ultra-violet spectra and the fluorescence analysis.
Piptadenia colubrina contains the same active principles as the species mentioned above.
All research workers who have studied the effects produced by these plants agree in attributing them to the presence of bufotenin and its oxide, of the alkyl derivatives of tryptamine and, among the latter, particularly of N.N-dimethyltryptamine and its oxide. Actually, from the point of view of their chemical structure, all these active principles are closely related to serotonin.
Pharmacological and Toxicological Data
Humboldt appears to attach greater importance to the presence in the compound of freshly calcined lime than to the active principles of the plant, as can be seen from the following passage:
“… It is not to be believed that the niopo acacia pods are the chief cause of the stimulating effects of the snuff used by the Otomac Indians. These effects are due to the freshly calcined lime” (Von Humbolt 1799).
However, the arguments with which this author supports his opinion are highly debatable; the fact that natives of the Popoyan Andes and the Goajiro Indians of the Lake Maracaibo district eat lime as a stimulant in order to increase the secretion of saliva and the gastric juices does not in any way mean that lime should be regarded as the active agent in the drug, particularly as the real effect of nopo is very far from being that of a mere stimulant of secretions.
De la Condamine has stated that the Omagua Indians of the Upper Maranon region also use a plate and inhaler to take curupa powder. Little doubt remains today that curupa and nopo are very similar, not to say identical. Fr. Gili says that the Otomacs give the name curupa to the drug nopo (Hamet 1956).
According to the classical descriptions, nopo might be said to have a two-phase action. During the initial period, or phase, the drug has a stimulating effect, producing great excitement in the subject and the onset of hallucinatory delirium. The symptoms vary widely according to the personality of the subject; the use and abuse of this drug, as is the case with many others such as alcohol, cannabis, etc. may produce very different effects according to the psychological characteristics of the person taking it. It is interesting to note that a primitive and barbarous tribe, such as the warlike Otomacs, use nopo as a stimulant before battle, whereas peaceful tribes like the Guahibos, take the drug for different purposes.
During the second phase, sleepiness is followed, according to most observers, by complete hypnosis. The drug in short, creates a very special kind of drunkenness accompanied by loss of reasoning power and finally by unconsciousness lasting for the duration of the hypnosis.
In preliminary experiments carried out in our laboratory in 1947 and 1948, we tested the action of the compound as used by the Guahibo Indians. To ensure adequate penetration of the prepared powder, we used a special device which has been described elsewhere. Using this device we administered the powder to mice and rats. The results obtained from our experiments can be summarized as follows:
White mice, weighing from 25-30 g. Shortly after inhaling the drug, generally at the end of three minutes, the animals showed signs of excitement, constantly rubbing their noses with their front feet. The powder appeared to produce intense irritation of the mucous membrane. Almost immediately afterwards, the animals started biting the wires of their cage and running about agitatedly. At the end of five or six minutes their breathing became hurried and irregular, reaching a state of dyspnoea. After eight minutes the nasal irritation appeared to be very intense. A minute or two later the animals had manifest difficulty in walking, as though they were drunk, and dragged their bellies along the floor of the cage. They opened and shut their eyes repeatedly until the blinking ended in ptosis of the eyelids. At this stage, the animals showed all the typical symptoms of drunkenness, comparable from every point of view, with those of a person intoxicated by alcohol. These symptoms appeared between fifteen and twenty minutes after the drug had been inhaled. Later on, small convulsive movements were noticeable. The animals rose up on their hindquarters and shook their bodies, as though they had hiccoughs and sharp contractions of the diaphragm were observed. Their heads swayed with a movement similar to that of a bell clapper. After from 35-40 minutes these symptoms ceased and the state of drunkenness alone remained. At the end of an hour they began to recover and tended to fall asleep.
White rats, weighing from 180 to 200 g.After three or four minutes these animals showed similar symptoms to those we have described in the mice, repeatedly rubbing their noses with their front feet. The irregular breathing was possibly more marked or, in any case, easier to see and assess. As well as the signs of drunkenness, much the same as in the mice, the rats scratched themselves all over; they seemed to be suffering from acute generalized itching, with slight multilocular paresthesia. After nine or ten minutes, they were seized with contortions, adopting all kinds of postures. While under the influence of the drug the rats did not react to external stimuli; the cage could be struck violently, a lot of noise made in the vicinity, the animal pushed around, blown on and generally molested, without being roused from its torpid condition. At the end of fifteen minutes the rats were completely stupefied and entered a semi-lethargic state, which lasted about forty-five minutes and sometimes as long as an hour or more.
In 1956, Raymond Hamet made a study of the pharmacological effects of an extract of Piptadenia peregrina.
It has now been demonstrated that the effects produced by the various extracts and preparations of these plants are due to the presence of bufotenin and the derivatives of tryptamine (chiefly dimethyltryptamine, or DMT).
A group of research workers at the Budapest Central Institute for Nervous and Mental Diseases has published a series of studies of great interest in this field. Among these, the following deserve special mention:
In 1956, Sai-Halasz submitted to the third International “Rorschach” Congress, held in Rome, his observations on certain aspects of the Rorschach test during experimental psychosis produced by DMT.
In the same year, St. Szara , another member of the group, published an initial report, supplemented a year later by a further paper, dealing with the effects of various tryptamine derivatives.
In 1957, Szara, in collaboration with Boszormenyi and Sai-Halasz described the results of further experiments in the same field.
In 1959, Sai-Halasz and Endroczy studied the effects of tryptamine derivatives on the behaviour of a dog under the influence of stimuli applied to the brain stem. These authors were also able to show that the intramuscular injection of DMT into human patients in doses of 0.8 mg per kg of body weight produced very marked psychotic effects, which began from four to six minutes after the injection and lasted from forty to fifty minutes. According to them: “The experimental psychosis is characterized by brilliantly coloured hallucinations and accompanied by very marked vagal symptoms, such as mydriasis, hypertension, dyspnoea and frequently by anxiety “. For the experiments carried out by them on dogs the animals had to be specially trained until they had developed a conditioned reflex to food; special electrodes were inserted to stimulate different cerebral areas. The results of this very interesting study were published by Elsevier in 1959, under the title: “Neuro Psychopharmacology “, which supplemented the work published by Sai-Halaisz, Brunecker and Szara a year earlier.
With regard to the effects produced by bufotenin, the following studies should be mentioned:
In 1955, Evarts and his collaborators described the psychoto-mimetic effects of bufotenin, (dimethylamino-5-hydroxytryptamine).
In 1956 Evarts supplemented his observations on this subject.
In the same year Fabing and Hawkins published an interesting paper, which was followed by another by Woods and his collaborators.
Later, in 1959, Costa and his collaborators studied the effects of the intravenous injection of bufotenin and Courvoisier and Leau analyzed the protective action of parenterally administered hydroxy-5-triyptamine (5HT) against bronchitis provoked in guinea pigs by the same substance applied in aerosols. At the same time, these scientists analyzed the protective action of bufotenin.
In one of his studies on psychoto-mimetic drugs, Plutarco Naranjo has summarized the principal effects of bufotenin and DMT. The following data are reproduced from his work:
Total duration (hours)
Fabing & Hawkins
Fabing & Hawkins
* Or. = oral; I.M. = Intramuscular; I.V. = Intravenous
The above data were obtained from experiments on human patients.
In short, it can be said that the most striking effects of these drugs are the following:
There are two main types of effects: psychotomimetic and neuro-vagal. These effects appear extremely quickly. Both types appear simultaneously. Bufotenin produces psychoto-mimetic effects, with polychrome hallucinations (very brilliantly coloured) similar to those produced by LSD-25, but of very brief duration.
DMT causes marked alteration of space-time perception, a tendency to “autism” (much greater than that provoked by mescalin) and delusions. As is well-known, in addition to its hallucinogenic effects, bufotenin produces passing psychoses, cyanosis, respiratory anxiety, sweating, paresthesia, mydriasis and nystagmus. In addition to its hallucinogenic effects, DMT produces psychosis and marked vagal phenomena (mydriasis, hypertension, dyspnoea, and anxiety).
Data concerning the mechanics of the drug’s action
It is not possible to claim that the mode of action of the drug has been completely clarified. However, certain data have been obtained which can be considered of special interest. Before summarizing these data we would recall the excellent general review of the subject by Turner and Merlis published in 1959.
Many researchers in this field have drawn attention to the possibility that bufotenin and DMT may in some way interfere with the metabolism of serotonin (5-hydroxytryptamine), by inhibitory action through competition, or by blocking certain enzymatic systems, etc.
It has been proved that serotonin is found chiefly in the diencephalic nuclei, in the “limbic system” and in the “reticular ascendant” system. Norepinephrin is also found in these formations and the important role of acetylcholine as a chemical mediator not only in the peripheric, but also in the central, synapses should not be overlooked. It has therefore been assumed that the normal transmission of nervous impulses through the systems mentioned above depends not only on the concentration of serotonin and norepinephrin, but also on the maintenance of a possible balance between these and acetylcholine; upsetting this balance might perhaps give rise to psychoto-mimetic effects.
Raymond Hamet is of the opinion that bufotenin can liberate catecholamines from their peripheric deposits. This finding gave Costa and his collaborators the idea that the same effect might be produced within the brain stem.
Woods and his collaborators think that bufotenin when it reaches the suprarenal glands, might possibly liberate catecholamines from the medullary part of the glands (Woods et al. 1956).
There is much that is still obscure about the complicated mechanics of the action of the components of the ancient drug used by the South American Indians. The present paper has been written with the object of keeping alive the interest of researchers in this very promising field.
Final considerations regarding the etiology of the custom of taking piptadenia
The chief causes and motives which lead various primitive tribes to make use of powdered piptadenia seeds would appear to be the following:
The need for an “excitant” before battle. We have already quoted various authorities on the use of this drug by the Otomac Indians for the sole purpose of procuring an intense stimulus which incites them to kill and wound their enemies. However, the arousing of aggressive tendencies does not appear to be common to all cases. The effect of the drug depends to a large extent on the “personality” of the subject under its influence. In more pacific tribes, as is shown in the case of the Guahibos, the drug does not promote aggressiveness.
The need of a suitable intermediary for “sacred invocation rituals.” In this respect, Lisandro Alvarado writes:”At the beginning of the twentieth century the most renowned among the witch doctors in the Upper Orinoco area was the Guahibo Piache from Ocune, at the source of the River Vichada, who was known as kuragina (Good Spirit) . . .
. . . at the end of this retreat, he takes yopo powder until he becomes terribly drunk, his intoxication provoking such violent spasms and delirium that he has to be assisted by his acolytes or relatives, and soon afterwards remains sunk in a deep lethargy…” (Alvarado 1945).
Further on the same author tells us:
“The Otomacs also had mojanes who made their prophecies preferably with the help of yopo, which was well known to them; but among these Indians, as among the Guahibos and Achaguas, yopo does not seem to have been a monopoly of the piaches used solely for prophesying purposes” (Alvarado 1945).
Use as a “vice “.The drug has been used in this way by many tribes from very remote times. The vice is encouraged particularly by: (a) the desire for an abnormal stimulant; (b) the desire to provoke a state of euphoria; (c) an emulative spirit and the maintenance of a tradition; (d) ignorance.
Another aspect of the question which should not be overlooked is the association of the drug with other toxic substances, especially alcohol and tobacco. In some regions the use of this drug is also associated with that of caapi (Banisteria caapi Spruce), another powerful hallucinogenic agent.
Alvarado, Lisandro. “Datos etnograficos de Venezuela.” (Biblioteca Venezolana de Cultura – Coleccion “Viajes y Naturaleza” – Escuela Tecnica Industrial, Talleres de Artes Graficas; Caracas, 1945.)
Bueno, Fray Ramon. “Apuntes sobre la Provincia misionera del Orinoco e indigenas de su territorio, con algunas particularidades” – Prologue by Mons. Nicolas E. Navarro. Caracas, 1933.
Cooper, John M. Stimulants and narcotics – in: Handbook of South American Indians Bureau of American Ethnology, Smithsonian Institution, Washington, Vol. 5.
Colon, Fernando. Historia del Almirante de las Indias D. Cristobal Colon. Coleccion de Fuentes de Historia de America, Buenos Aires, 1944. (Historia del Almirante de las Indias D. Cristobal Colon; Madrid, 1892.)
Costa, E., Himwich, W. A. & Himwich, H. E. Neuro-Psychopharmacology (Elsevier, Amsterdam, 1959), pp. 299-303.
Courvousier, S. & Leau, O. Ibid: 303-308.
De La Condamine, Ch. M. “Relacion abreviada de un viaje por el interior de la America Meridional, desde la costa del Mar del Sur hasta las costas del Brasil y de la Guayana, siguiendo el rio de las Amazonas.” (Spanish translation by Federico Ruiz Morcuende of the Account of the journey made in 1743 – Madrid, 1921.)
De Las Casas, Fray Bartolome. “Historia de las Indias”, edited by el Marques de Fuensanta del Valle and Don Jose Sancho Rayon, Madrid. – In Coleccion de doc. iniditos para la Historia de Espana. See also: “Apologetica historia sumaria cuanto a las cualidades, dispusicion, descripcion, ciclo y suelo destas tierras, y condiciones naturales, policias, republicas, maneras de vivir e costumbres de las gentes destas Indias Occidentales y Meridionales, cuyo Imperio soberano pertenece a los Reyes de Castilla”. Biblioteca de Autores Espanoles: Obras escogidas de Fray Bartolome de las Casas, III, Apologetica Historia. Edio critico y preliminar por Juan Perez de Tudelo Buesco. Ediciones Atlas, Madrid, 1958.
Dijour, Elisabeth. Published by “Societe des Americanistes de Paris”.
Evarts, E. V. Arch. Neurol. Psychiat., 75: 49; 1956.
Evarts, E. V., Landau, W., Freygang, W. & Marshall, W. H. Am. J. Physiol., 182; 594; 1955.
Fabing, H. D. & Hawkins, J. H. Science, 123; 886; 1956.
Fisch, M. S., Johnson, N. M. & Horning, E. C. – J. Am. Chem. Soc., 77 (22): 5892-5896; Nov. 20, 1955.
Flury, Lazaro. “El Caa-pi y el Hataj, dos poderosos ilusiogenos indigenas”. America Indigena, XVIII (4): 293-298; October 1958.
Gili, P. Salvatore (Salvator Gilius). “Saggio di Storia Americana, etc.” (Per Luigi Perego Erede Salvioni – Stampator Vaticano nella
Granier-Doyeux, Marcel. Boletin de la Oficina Sanitaria Panamericana, 27 (No. 2): 156-158; Feb. 1948.
Granier-Doyeux, Marcel. “Acerca de una toxicomania indigena; el uso de la Piptadenia peregrina (Nopoo Yopo)”. Gaceta Medica de Caracas, Ano LVI (No. 13-18): 161-175; July-September 1948.
Granier-Doyeux, Marcel. “El uso de la Piptadenia peregrina (Nopo o Yopo)” (Rev. Tecn. Polic., Ano II (No. 8): 49-55; March-April 1956.)
Gumilla, Padre Jose. “El Orinoco Ilustrado, Historia Natural, Civil y Geografica de este gran rio, y de sus caudalosas vertientes, etc.”, con Licencia. Madrid: por Manuel Fernandez, Impressor de la Reverenda Camara Apostolica, en su Imprenta y Libreria, frente la Cruz de Puerta Cerrada. 1741.
Hamet, Raymond. Compt. rend. Soc. Biol., 137: 74 & 744; 1943.
Hamet, Raymond. Comptes rendus, 243 (5): 512; 1956.
Koch-Gruenberg, Theodor. “Zwei Jahre unter den Indianern” (Berlin 1909-1910).
Kunth, C. S. “Synopsis Plantarum Aequinoctialium Orbis Novi, etc.” – (Parisiis, apud F. G. Levrault, bibliopolam, via dicta M. le
Prince, No. 31, atque Argentorati, via dicta des Juifs, No. 33-1822). 1839.
Lopex de Gomara, Francisco. “Historia de las Indias y Conquista de Mexico” (Saragossa, 1552).
Naranjo, Plutarco. Archivos de Criminologia, Neuropsiquiatria y disciplinas conexas, 2 a Epoca, VI (No. 23): 358-379; July-September 1958.
Pittier, Henri. “Manual de Plantas usuales de Venezuela” (Lit. y Tip. del Comercio; Caracas, 1926.)
Rivero, Padre Juan. “Historia de las Misiones de Casanare y rios Orinoco y Meta, 1729-1735.” (” Papel periodico ilustrado”, Bogota, 1883).
Sai Halasz, A., Brunecker, G. & Szara, St. Psychiat. Neurol., Basel 135; 285; 1958.
Sai-Halasz, A. & Endroczy, E. Neuro-Psychopharmacology (Elsevier, Amsterdam, 1959), pp. 405-408.
Sai-Halasz, A. Aspetti Rorschach durante la psicosi sperimentale indotta dalla dimetil-triptamina. 3rd International Rorschach Congress, Rome, 1956.
Szara, St. Experientia, 12: 441; 1956.
Szara, St. in S. Garattini & V. Ghetti, Psychotropic Drugs, Elsevier, Amsterdam, 1957 (p. 460).
Szara, St. Buszormenya, Z. & Sai-Halasz, A. Acta Physiol. Acad. Sc. Hung., Suppl. II: 78; 1957.
Turner, W. J. & Merlis, S. A.M.A. Arch. Neurol. Psychiat., 81: 121; 1959.
Von Humbolt, Alexander. “Voyage aux regions equinoxiales du Nouveau Continent, fait en 1799, 1800, 1801, 1802, 1803 et 1804, par Al. de Humboldt et A. Bonpland, redige par Alexandre de Humboldt; avec un atlas geographique et physique.” (Librairie Grecque-Latine-Allemande, rue des Foss?s-Montmartre, No. 14, Paris.)
Wilbert, Johannes. “Zur Kenntnis der Yabarana” (Naturwissenschaftliche Gesellschaft La Salle, Caracas.
Antropologica Supplementband No. 1 – Cologne, 1959).
Willdenow, C. L. “Linnaei species plantarum” (Berlin, 1798-1826).
Williams, Llewelyn. “Exploraciones botanicas en la Guayana Venezolana” (Tip. La Nacion; Caracas, 1942).
Woods, E. F., Richardson, J. A., Richardson, A. K. & Bozemen, R. F. J. Jr. Pharmacol. Exptl. Therap., 116: 351; 1956.
Zerries, Otto. “Los indios Guaika y su situacion cultural” (Informe preliminar de la Expedicion Frobenius al Alto Orinoco) – Boletin Indigenista Venezolano, Ano II – Tomo II (No. 1-4): 61- 77; January-December 1954.
Reprinted with permission from Bulletin on Narcotics Issue 17, Volume 2: 29-38, 1965