An investigation has been carried out in connection with fine material of the order of a few microns suspended in water. It was desired to treat approximately 1 200 000 gal per day and to substitute ultrasonic methods for poacher house pits. A bibliography and study of work done to date indicate that no systematic study has been made in this field. Tests were made at cavitation and below‐cavitation levels at several different frequencies ranging from 20 kc to 1 Mc. Breakdown of the fine material into small uniform particles was observed at cavitation levels and agglomeration at levels under those necessary for cavitation. All tests were made on laboratory samples. Every test was repeated a number of times to determine reliability. Results indicate that the method has promise for accomplishing the results desired. [The work was sponsored by Hercules Powder Company and the Radford Arsenal.]