The laity, heathen and Christian, positively do not know from what particular tree the leaf or piece of bark was obtained, and they would not be able to recognize it even if they were allowed to see it. They see only the dry powder or ashes. Even if the heathen laity were able to tell me, they will not do so. Even if they were bribed, I would have no certainty that they were showing me the plant that was actually used; for they would know that I would have no means of comparing specimens or of proving their deception. The native will tell foreigners many things for friendship or for regard, and he enjoys conversation with us; but superstition slams his heart's door shut when he is asked to reveal secrets of the spirits. His prompt thought is: "White man's knowledge has given him power. There is little left of land, authority, women, or wealth in my country that he has not seized. Shall I add to his power by telling him the secrets of my spirits?" Of course the magic doctor will not tell. That would be giving himself entirely away. Even Christian men and women who have inherited from a parent knowledge of some plant, and who use it rationally for its purely medicinal quality without any reference whatever to spiritual influences, can barely be induced to tell me of it. The fee they obtain is part of their means of living. They make honest "medicine" in the circle of their acquaintances for certain sicknesses for which their drug happens to be fitted. Of a cure for any other sickness they know nothing, and must themselves go to some one else who happens to possess the knowledge.