The moment the sticky sap of the kiracaguero tree is poured into the poisonous and concentrated liquid, kept boiling, it blackens and coagulates to become rather like tar or a thick syrup. This mass is the curare that is sold inside crescentia fruit; but as its preparation is in the hands of a few families, first-class curare from Esmeralda and Mandavaca is sold at high prices. When dried this substance looks like opium, but it attracts humidity if exposed to air. It tastes agreeably bitter, and Bonpland and I have often swallowed little bits. There is no danger as long as you make sure your gums and lips are not bleeding. The Indians regard curare taken by mouth as an excellent stomachic. The way the poison is made is rather similar everywhere, but there is no certainty that different poisons sold under the same name in the Orinoco and Amazon are identical or from the same plant.