This indicates the following concept: When two coins have the same face value, but are made at different costs are circulated at the same time, people collect coins with a higher value (high-quality coins) and keep them, not using them, or melt them to mint many lower-quality coins, and therefore, high-quality coins disappear from the market and inflation ensues.
価値の異なる原価をもった同一額面の通貨が同時に流通しようとするとき、人々は原価の高い貨幣（良貨）を集めて死蔵し、あるいはそれを元手に融解して多くの悪貨を生み出し、良貨が市場から消滅してインフレを招くという考え方。