In English
We consume pure food and water; but in a very short time, it gets converted into impure matter fit only for excretion. It is not easy to distinguish between what is pure food and pure water and what is not. We should not leave it at that, considering it to be or a natural phenomenon. In nature, there will be impurities at first and we have to transform them by suitable processes. Scientists, especially those belonging to the geological department, know this very well. When they prospect for gold, they find out the spot where gold occurs, then dig deep into the earth and find gold-bearing quartz. In its natural state, gold is found to be in the company of other impurities. At a later stage, they purify the impure mass and get pure gold from it.