土耳其爱琴海沿岸盛产大量压碎的未加工珍珠岩，人们对其作为滤层中沙子替代品的适用性进行了检查。比较了筛分分析、孔隙率、颗粒密度和在20%浓盐酸中的溶解度试验结果以及珍珠岩和砂的成本。表8包括参考文献。

Crushed raw perlite, which is plentiful along Turkey's Aegean Coast, was examined for its suitability as a substitute for sand in filter beds. Sieve analysis, porosity, particle density, and solubility in 20 percent concentrated HCl acid tests results as well as the costs of perlite and sand were compared. Includes 8 references, tables.