V originále
The method how to separate shells from other mineral matter has been well known for many years. In particular this method is based on the fact that empty shells are filled with air and therefore float on the water surface, whereas other mineral matter sinks down. However, in mires this method is not optimal. In mires, empty shells are filled with water. Therefore, both empty shells and living animals sink down in the course of washing. The present method is based on this fact.