"What is this deadly poison that was used on Mendoza?" I managed to ask.
"You have been fortunate enough to obtain a sample of it from the Museum of Natural History," returned Craig. "It comes in a little gourd, or often a calabash. This is in a gourd. It is a blackish, brittle stuff, incrusting the sides of the gourd just as if it was poured in in the liquid state and left to dry. Indeed, that is just what has been done by those who manufacture it after a lengthy and somewhat secret process."
He placed the gourd on the edge of the table, where we could see it closely. I was almost afraid even to look at it.
"The famous traveller, Sir Robert Schomburgk, first brought it into Europe, and Darwin has described it. It is now an article of commerce, and is to be found in the United States Pharmacoepia as a medicine, though, of course, it is used in only very minute quantities, as a heart stimulant."
Craig opened a book to a place he had marked. "Here's an account of it," he said. "Two natives were one day hunting. They were armed with blow-pipes and quivers full of poisoned darts made of thin, charred pieces of bamboo, tipped with this stuff. One of them aimed a dart. It missed the object overhead, glanced off the tree, and fell down on the hunter himself. This is how the other native reported the result:
"'Quacca takes the dart out of his shoulder. Never a word. Puts it in his quiver and throws it in the stream. Gives me his blow-pipe for his little son. Says to me good-bye for his wife and the village. Then he lies down. His tongue talks no longer. No sight in his eyes. He folds his arms. He rolls over slowly. His mouth moves without sound. I feel his heart. It goes fast and then slow. It stops. Quacca has shot his last woorali dart.'"
Leslie and I looked at Kennedy, and the horror of the thing sank deep into our minds. Woorali. What was it?
"Woorali, or curare," explained Craig slowly, "is the well-known poison with which the South American Indians of the upper Orinoco tip their arrows. Its principal ingredient is derived from the Strychnos toxifera tree, which yields also the drug nux vomica, which you, Dr. Leslie, have mentioned. On the tip of that Inca dagger must have been a large dose of the dread curare, this fatal South American Indian arrow poison."
"Say," ejaculated Leslie, "this thing begins to look eerie to me. How about that piece of paper that I sent to you with the warning about the curse of Mansiche and the Gold of the Gods. What if there should be something in it? I'd rather not be a victim of this curare, if it's all the same to you, Kennedy."
Kennedy was thinking deeply. Who could have sent the messages to us all? Who was likely to have known of curare? I confess that I had not even an idea. All of them, any of them, might have known.