Many of our common medicines were first discovered from plants, later synthesized to make them more available. But in the Amazon, for example, there are 80,000 species of plants. To give you some measuring rod, New England has 1,900 only. Eighty thousand species! If chemists are going to try to get material of 80,000 species and analyze them, and then give them to pharmacologists, this job will never be done, never be finished. What we should do is concentrate on those plants that people in these societies have found have some effect on the human body. We may never use the chemicals in them. We may use them for the same purpose in some cases. We may use them for completely different reasons.
For example, what took me first to South America was to study arrow poisons, which in 1941 were becoming very important in medicine. They are important today, as the extracts are used as muscle relaxants before surgery. But here is a case: the Indian uses these poisoned arrows to kill; we are using them to help preserve life, completely different uses. Another example is rotenone. The natives fish by throwing bark into still water in the Amazon, and these plants have rotenone in them. Now we don’t want to poison our rivers any more than they are poisoned. We’d have no fish! But rotenone now is our best biodegradable insecticide. It can be spread over thousands of acres against insect damage, and in two or three days it is broken down, and it doesn’t carry through and poison plants and animals and eventually human beings.
Some of my work may eventually pan out to be of help to humanity as a whole. I just published a book in which, in my small area of the Amazon, in the Republic of Colombia, we have 1,600 species of plants used as medicines or poisons by the natives. And, I am certain that in my 47 years of work there, I must have missed a lot. But, you can imagine 1,600 — when the whole flora of my part of the United States, New England, has only 1,900, these people use at least 1,600!