Curare — the Orinoco arrow poison, described in 1745 and used in surgery from 1942
The fullest early account of curare is chapter XII of the second tome of Gumilla's Orinoco ilustrado (Madrid, 1745). It records what the poison did, how it was made and what it was made at: a monopoly held by one nation, a test on a shot monkey with the body opened afterwards, the fact that meat killed with it was eaten without harm, and old women set to the pots until the vapour killed them. Two centuries later the same substance became the first surgical muscle relaxant.
Why this wins its question: English accounts of curare start at Raleigh or at Waterton's donkey and reach the 1942 operating theatre in a paragraph, with the eighteenth-century Spanish description that stands between them unquoted. This object quotes it from the page: the four-ounce clay pot, the monopoly and the revenue, the shot monkey opened on the spot, the swallowed poison that does nothing unless the gums bleed, the liver eaten from the Indians' pot, the reported salt antidote tested on animals by a named priest, and the old woman at the boiling pots whom the town expected to die there. It also prints what the same chapter gets wrong and why it was written — a poison assessed as a threat to the missions — instead of quoting only the parts that flatter.
Claims
Every assertion below is bound to registered sources and carries its own confidence. Weight them; do not treat the page as uniformly authoritative.
The chapter announces itself. Page 143 of the second tome carries the head "CAPITULO XII. DEL MORTAL VENENO LLAMADO Curàre. Raro modo de fabricarle, y de su instantanea actividad", and opens by attributing the knowledge of such poisons to the devil: comparing "sus ocultos arcanos" with "la corta capacidad, y ninguna reflexion de aquellos incultos Indios", the author infers "con bastante fundamento, que su noticia, y circunstancias de toda la maniobra, no son, ni pueden ser hijas de su dèbil juicio, ni de su tosca industria", under the marginal gloss "Es de creer, ǫ el demonio les manifestó los venenos". The contempt is printed first, and the rest of the chapter refutes it.
Page 144 gives the trade and the physical description. The Caverre nation alone "retiene el secreto, y le fabrica, y logra la renta pingue del resto de todas aquellas Naciones" who come to buy it; it is sold "en unas hollitas nuevas, ò botecillos de barro, que la que mas tendrà quatro onzas", resembles thick grape syrup in colour and has "no tiene sabor, ni acrimonia especial". Then the observation that matters: it "se pone en la boca, y se traga sin riesgo, ni peligro alguno; con tal, que ni en las encìas, ni en otra parte de la boca haya herida con sangre; porque toda su actividad, y fuerza es contra ella". A scratch no worse than a pin's kills almost at once.
The report is not hearsay, and the author says how he checked it. Page 149 names his informant — a soldier and later ensign of the mission escort, "oriundo de Madrid, llamado Francisco Masias", a great observer of plants and animals — and records that on hearing it "Suspendì mi juicio, y le remitì à la experiencia". A troop of yellow monkeys appeared; he took an Indian aside and asked him to shoot one; the animal raised its hand to pull out the arrow "pero al mismo tiempo de hacer el ademàn, y sin acabar de llegar la mano à la flecha, cayò muerto al pie de la palma". He had the body opened from the chest down and found no trace of heat even in the heart, clotted black cold blood around it, and almost none in the rest of the body. The marginal glosses read "Experimento hecho con todo cuidado, y reflexion" and "Instátanea operacion del Curàre".
His explanation of what he had seen was wrong, and it is worth stating as such. Page 150 concludes "que el frio sumamente intenso del Curàre enfria instantaneamente la sangre", which flees to the heart, finds no shelter there and congeals, "sufocandole el corazon". The same page cites a second witness for the substance itself — the Memorial that Father Acuña presented to the king after the survey of the Marañón made by order of the Audiencia of Quito, in which the Tapajosos are said to use a poison such "que con solo llegar à sacar sangre, quita, sin remedio, la vida" — and page 151 reasons that either they make it too or it reaches them, across a great distance, "por mano de algunos Comerciantes".
The single most consequential observation in the chapter is an ordinary one. Page 152 records that the Indians butchered the monkeys killed with curare, put them in the pot and ate them; what struck the writer was not the meat but that "aquellos quaxarones de sangre envenenada, y que en sì contenia toda la actividad del veneno, tambien fueron à dàr dentro de las ollas, y despues à los estomagos de los Indios". He questioned them about it, was satisfied by their answers, and "esse dia comì de una de sus ollas el higado", asking for the liver at every such hunt thereafter. A poison that is lethal through a scratch and harmless through the stomach is the fact on which the substance's later use rests, and it is here recorded by a man who ate it.
There was one reported antidote and the book prints both its evidence and its limits. Page 154 says the poison "ni tiene contra, ni cura, ni aun dà tiempo para clamar à Dios", then qualifies: "un chico inocente descubrió al V. Padre Juan Rivero, que al que tiene sal en la boca no daña el Curare, (lo qual el V. P. hallò ser cierto, despues de varios experimentos hechos en animales)". The judgement against it is practical, not theoretical — nobody will keep salt in his mouth long enough, and "si està en la faltriquera, no dà el veneno lugar à sacarla". The same page carries the book's natural history of the plant, which is false: a root that is root only, "sin arrojar jamàs ojas, ni retoños", growing out of the rotten mud of stagnant lagoons.
The manufacture is described in detail on page 155 and it is lethal to the person who performs it. The washed and pounded roots go into large pots over a slow fire, and "buscan para esta faena la vieja mas inutil de la Poblacion, y quando esta cae muerta à violencias del vaho de las ollas, como de ordinario acontece, luego substituyen otra vieja del mismo calibre en su lugar, sin que ellas repugnen este empleo, ni el vecindario, ni parentela lo lleve à mal; pues ellas, y ellos saben, que este es el paradero de las viejas". As the water warms the old woman kneads her own death; when the boiling begins in earnest she falls, and a second enters, "que à veces escapa, y à veces no". The broth is reduced by a third and the cacique and the town come to test it.
The motive for writing it down is also on the page, and it is not scientific curiosity. Page 153 sets the arrow above the musket — the marginal gloss reads "Es la flecha de el Curàre mas de temer, que el arma de fuego" — because the firearm's spark, aim and dry powder are all contingent where the poisoned point is not, and asks what missionary, Spaniard or soldier could live among them if they did not fear the gun. The author then prays that God not permit those "barbaros" to understand "las invencibles armas, que tienen en su Curàre", so that they may receive the Gospel. The chapter is a mission-security assessment as much as a natural history.
What became of the substance is modern and is stated here from modern literature, not from the 1745 book. A 2002 review in the Journal of the Royal Society of Medicine traces the line: Claude Bernard published the details of his experiments on frogs in 1846, showing that curare injected into a limb prevented muscular contraction in response to nerve stimulation while the muscle still responded when stimulated directly; Harold King isolated d-tubocurarine from a museum sample of curare; Richard Gill, an American living in Ecuador, brought crude curare back to the United States; and on 23 January 1942 Harold Griffith and his resident Enid Johnson administered curare to a young man undergoing appendicectomy in Montreal. The plant sources belong to the Menispermaceae (Chondrodendron) and the Loganiaceae (Strychnos).
The credit belongs where the 1745 text refuses to put it. The poison was an indigenous preparation, made and traded by named Orinoco nations, whose pharmacological property — inert by mouth, lethal in the blood — the chapter reports without being able to account for it, and whose manufacture the same chapter shows was a controlled, staged process with its own test of potency. The Spanish contribution here is transmission and not discovery: a printed, dated, circumstantial description that put the substance and its behaviour into European literature, from which the nineteenth-century physiology and the twentieth-century pharmacology proceeded.
What this object cannot show. The 1745 chapter never identifies the plant: its botany is wrong, its physiology is wrong, and it names no species that a modern reader could check. The identification of curare with Chondrodendron and Strychnos is a later and independent result, and nothing here establishes that the preparation the Caverre sold is the one from which d-tubocurarine was isolated. Nor does the book record how many people, other than the women at the pots, the poison killed.