In certain investigations it is desirable to determine rapidly the approximate density or specific gravity of small amounts of solids the available weight of which renders the employment of the usual means impracticable. The simple instrument termed the microdensimeter has been found useful and is particularly recommended as an aid in the rapid identification of fragments of material. The narrow graduated tube is partially filled with a liquid and the level is read. Then a weighed portion of the coarsely powdered material is introduced into the tube and the rise of the liquid level in divisions is noted.