Silver containing lead as an impurity is not purified by

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which method is not suitable for purifying silver that contains lead as an impurity.

2. **Identifying the Methods**: The two methods mentioned are:
- Pollen (likely a misinterpretation of "pollution" or "pollen" in the context of metallurgy)
- Cupellation

3. **Analyzing Pollen**:
- Pollen is not a recognized method for purifying metals. In metallurgy, it seems there is confusion here, as "pollen" does not refer to a purification technique.
- Therefore, it can be concluded that silver cannot be purified by this method.

4. **Analyzing Cupellation**:
- Cupellation is a well-known refining process used in metallurgy. It involves heating ores or alloyed metals at high temperatures to separate noble metals like gold and silver from impurities such as lead, copper, and zinc.
- Since cupellation is a recognized method for refining silver, it is not the answer to the question.

5. **Conclusion**: Based on the analysis, the method that does not purify silver containing lead as an impurity is **Pollen**.

**Final Answer**: Silver containing lead as an impurity is not purified by **Pollen**.

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