Prabhupada's lecture - Śrīmad-Bhāgavatam 1.10.5 - Mayapura, June 10, 1973
So everything in nature has to give something. That is the order. Everything that we see, nadyaḥ, the river... Why God has created the river? It has got a function. Similarly samudrāḥ, the oceans, similarly the hills, mountains, girayaḥ, savanaspati, vegetables. All these vegetables which are growing, each and every vegetable, creeper, has some service, we do not know. Because we do not know the use of these vegetables, creepers, we go to the doctor, physician. Otherwise, if somebody is ill, the medicine is there. We do not know how to utilize it. Still in remote villages, in forest, they do not come to the physician, doctors. The bils, the aborigines, they know so many drugs. For toothache, we go to the dentist and they extract the teeth, but I have read in Ayurvedic medicine, there is a drug, a root. Only if you touch this side of the mouth, all the germs collected within the teeth will come out. I have seen it.
Sometimes in the year 1931 or '32 I had a very severe tooth pain. So I was taken by my servant in the jungle to some, this vaidya. They cured me, and the dentist could not. I attended so many times to the dentist. I have got my practical experience. And in the Ayurvedic literature there is mention some drug, the root only if you touch here, the germs collected in the teeth, they will come out in the corner of the teeth some germs—sometimes it is itching; there is all germs—so they will come out. Sometimes pains in the toe. All they are germs. The germ theory is all right, but they want to cure these germs in different way. But by nature's way there are so many drugs and roots and creepers that can cure all the diseases.