"The famous traveller, Sir Robert Schomburgh 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 Pharmacopoeia 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:
"At least one person in this room will appreciate the local colour of a little incident I am going to read--to illustrate what death from this poison is like.Two natives of the part of the world whence it comes 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.'"We looked at each other, and the horror of the thing sank deep into our minds.Woorali.What was it? There were many travellers in the room who had been in the Orient, home of poisons, and in South America.Which one had run across the poison?
"Woorali, or curare," said 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."A great light dawned on me.I turned quickly to where Vanderdyke was sitting next to Mrs.Ralston, and a little behind her.His stony stare and laboured breathing told me that he had read the purport of Kennedy's actions.
"For God's sake, Craig," I gasped."An emetic, quick--Vanderdyke."A trace of a smile flitted over Vanderdyke's features, as much as to say that he was beyond our interference.
"Vanderdyke," said Craig, with what seemed to me a brutal calmness, "then it was you who were the visitor who last saw Laura Wainwright and John Templeton alive.Whether you shot a dart at them I do not know.But you are the murderer."Vanderdyke raised his hand as if to assent.It fell back limp, and I noted the ring of the bluest lapis lazuli.
Mrs.Ralston threw herself toward him."Will you not do something? Is there no antidote? Don't let him die!" she cried.
"You are the murderer," repeated Kennedy, as if demanding a final answer.
Again the hand moved in confession, and he feebly moved the finger on which shone the ring.
Our attention was centred on Vanderdyke.Mrs.Ralston, unobserved, went to the table and picked up the gourd.Before O'Connor could stop her she had rubbed her tongue on the black substance inside.It was only a little bit, for O'Connor quickly dashed it from her lips and threw the gourd through the window, smashing the glass.
